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Flashcards in CANINES Deck (239):
1

Which of the following clinical signs is not consistent with discoid lupus erythematosis in dogs?

a. Alopecia and crusting the muzzle, lips, and periorbitally

b. Depigmentation of the nasal planum

c. Loss of "cobblestone" appearance of the nasal planum

d. Hyperpigmentation of ventral abdomen

d. Hyperpigmentation of ventral abdomen

Clinical signs consistent with DLE include depigmentation, erythema, scaling, and loss of the "cobblestone" appearance of the nasal planum. Alopecia, crusting, scaling, and ulcerations can also be seen on the face, muzzle, lips, pinnae, and periorbitally

2

You are presented with a bitch that whelped her first litter 2 weeks ago. Two of the pups have died and the remaining 2 have neurological signs, suckle poorly, and cry constantly. Which of the following choices is the primary differential diagnosis?

a. Canine herpes virus

b. Canine parvovirus

c. Neonatal septicemia

d. Transplacental roundworm infection

e. Congenital disease

a. Canine herpes virus

Canine herpes virus (CHV) rarely causes disease other than mild respiratory signs in adult dogs. However, naive newborn pups have high morbidity and mortality if infected at less than 3 weeks of age. Naive bitches should be exposed to CHV prior to breeding or the bitch and pups quarantined for 3 weeks before and after whelping. Canine parvovirus in neonates can cause vomiting, diarrhea, or acute death due to cardiovascular failure in pups 3-8 weeks old

3

A 2-year old male neutered cat presents to you depressed, hypersalivating, and ataxic with muscle tremors. The owner reports that a pyrethrin-based spot-on formulation for flea control belonging to their Golden Retriever was accidentally applied on the cat earlier today. Which of the following drugs will you use to treat the cat's clinical signs?

a. Methocarbamol

b. Amoxicillin

c. Acepromazine

d. Atropine

e. 2-PAM

a. Methocarbamol

Pyrethrins alter the activity of the sodium ion channels of nerves, which prolongs the period of sodium conductance. This increases the length of depolarization resulting in repetitive nerve firing. Cats are particularly sensitive to pyrethrin-containing products and can develop clinical signs within hours after administration. Affected animals should be bathed to remove remaining product. Minor clinical signs such as hypersalivation and ear twitching are usually self-limiting and do not require treatment. Control of marked tremors or seizures can be achieved with methocarbamol (Robaxin).

4

A 7-year old female spayed Standard Poodle presents with weakness and lethargy. A chemistry panel shows a Na+ = 130 mEq/L (142-152 mEq/L), K+ = 6.5 mEq/L (3.9-5.1 mEq/L), BUN 55 mg/dl (8-28 mg/dl), creatinine 1.9 mg/dl (0.5-1.7 mg/dl). The test to run for a definitive diagnosis would be which of the following?

a. Electrocardiogram

b. Thoracic radiographs

c. ACTH stimulation test

d. Bile acids test

c. ACTH stimulation test

The chemistry profile above is highly suggestive of hypoadrenocorticism. An ACTH stimulation test would give a definitive diagnosis for Addison's disease if the plasma cortisol concentration is low after ACTH administration. A bile acids test is not indicated since liver function is not in question. Thoracic radiographs may show microcardia, hypoperfused lungs, and rarely megaesophagus. ECG abnormalities would be consistent with hyperkalemia, which includes wide, flat, or absent P waves, widened QRS complexes, tall spiking T waves, and bradycardia.

5

A 5 year old female spayed Cocker Spaniel is presented with a strange expression. Her right ear and lip appear to drop. There is ptosis O.D. (right eye) and the dog is drooling on the exam table. What anatomic structure is damaged?

a. Facial nerve

b. Left side inner ear
c. Trigeminal nerve

d. Right side inner ear

e. Left side medulla, motor intact

a. Facial nerve

Think of facial nerve paralysis (CN 7) with a unilaterally droopy face. Remember the facial nerve is motor to the muscles of facial expression (explaining the right side dropped ear, lip and eyelid) and innervates the lacrimal and salivary glands. Loss of innervations can lead to a dry eye, and possibly to exposure keratitis if animal losses ability to close eyelid from damage to facial nerve innervation of the orbicularis oculi muscle. Idiopathic in 75% of canine cases (25% of cats) Can also see these signs with middle ear damage (from otitis media), from facial nerve trauma (ear surgery in dogs, or pressure from halter buckles in anesthetized horse), or neoplasia Follow this link to see a horse with facial nerve damage: note the nose pulled to horse's left. (means facial nerve damaged on right). Think more of a dropped jaw with trigenimal nerve neuropathy (CN 5-dogs, horses).

6

You are called out on a house-call to see the 3-year-old male Labrador Retriever shown in the photo below. He presents for bilateral periocular edema (see photo) and facial pruritus. This has been a recurrent problem for the last 4 months. The owners reported the dog would be normal for several days, and then acutely develop the periocular swelling and itching. These episodes always happened while the dog was inside the house.

The previous episodes would last for several hours, and then the edema would resolve en route to the veterinary clinic. After each episode, the dog had some residual periocular or facial pruritus for 1-2 days.

You perform conjunctival swabs and aspirates of the edematous area which reveal large numbers of eosinophils.

What is the most likely underlying cause of the dogs signs?

a. Bacterial infection

b. Parasitism

c. Hypersensitivity

d. Autoimmune disorder

e. Neoplasia

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c. Hypersensitivity

Edema as you see here is a common clinical sign of a type I hypersensitivity reaction or allergy. The intermittent nature of the episodes suggests some type of allergic reaction, most likely infrequent contact with a potent allergen to which the dog has become sensitized. An underlying allergic etiology is further supported by the presence of eosinophils.

Identifying the underlying allergy in cases like this one can be challenging, and a thorough history and investigation of the dog's environment is warranted.

The other answer choices presented are less consistent with the recurrent and sudden clinical signs that are repeatedly observed.

7

A 12-year-old mixed breed female spayed dog presents with a several-month history of lethargy, hair loss, and greasy skin. The patient's face, feet, and tail are not clinically affected and she is mildly pruritic. This photomicrograph shows the results of impression cytology obtained from the patient. What is the most likely name of the organism pictured?

a. Staphylococcus pseudointermedius (Staphylococcus intermedius)

b. Malassezia globosa

c. Malassezia pachydermatis

d. Staphylococcus hyicus

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a. Staphylococcus pseudointermedius (Staphylococcus intermedius)

Intracytoplasmic cocci from a dog's skin are most likely Staphylococcus pseudintermedius (formerly called Staphylococcus intermedius), which is the species host-adapted to canines. Staphylococcus hyicus is host-adapted to pigs, so is less likely to be isolated from a dog. Malassezia (yeast) organisms are much larger than cocci and are not observed within the cytoplasm of neutrophils.

8

A 3-year old West Highland White Terrier presents for flea allergic dermatitis. The owner is concerned because she is on an appropriate adulticide and insect growth regulator, but live fleas are still being found on the patient. Additionally, the dog also has moderate signs of flea allergy dermatitis; papular/pustular dermatitis in the lumbosacral region. Why might the treatment be failing?

a. Owner is not applying the product properly and not treating the environment

b. Owner is not treating the environment

c. Owner is not applying the product properly

d. Owner is not applying the product properly and is not treating other pets in the household

e. Owner is not applying the product properly, owner is not treating the environment, and other pets in the household are not on flea control

f. Other pets in the household are not on flea control

e. Owner is not applying the product properly, owner is not treating the environment, and other pets in the household are not on flea control

This question is a review of the most common reasons for failure of a flea product to work. Education is extremely important when starting flea treatment. Always question how the owner applies the product, whether the environment is being treated, and make sure all pets in the household are undergoing treatment. One is often surprised how many owners apply topical products just to the hair of their animals. Many owners (and veterinarians) blame lack of response to resistance against flea adulticides; however, it is much more likely (in the majority of cases) that it is due to one of these 3 listed reasons.

9

A four-year old Labrador Retriever presents with an aural hematoma of the right ear. Given the cytological findings from an ear swab as seen in this image, which one of the following ear cleaning combinations will you not send home with your patient?

a. Mometasone, gentamicin, clotrimazole

b. Thiabendazole, neomycin, and dexamethasone

c. Gentamicin, betamethasone valerate, and clotrimazole

d. Neomycin, bacitracin, and polymyxin B

d. Neomycin, bacitracin, and polymyxin B

This patient has a high number of malassezia yeast visualized on cytology. This organism can be responsible for perpetuating otitis externa. It is not unusual to see yeast in the ear canal of a dog; however, yeast numbers of greater than 5 per high powered field can be considered abnormal.

Other clinical signs of otitis externa may include ear pain, pruritis, aural discharge, bad odor, and neurologic signs.

Effective treatments for uncomplicated otitis externa typically contain an antifungal, antibiotic, and an anti-inflammatory. Since this dog primarily has a yeast infection it is imperative that the ear medication prescribed has an anti-fungal. The answer choices provided are commonly known as triple antibiotic ointment (neomycin, bacitracin, and polymyxin B), Tresaderm (thiabendazole, neomycin, and dexamethasone), Mometamax (mometasone, gentamicin, clotrimazole), and Otomax (gentamicin, betamethasone valerate, and clotrimazole). Note that the triple antibiotic ointment does not contain an anti-fungal.

Additionally, the ears should be cleaned before applying the ear medication. Many ear cleaners contain antifungals too (Triz Ultra + Ketoconazole), which may enhance treatment response.

10

Demodicosis often coincides with bacterial infections. On a recheck examination of an 8-month old pit bull with demodicosis you find swelling and furunculosis over the lateral thighs that is draining serosanguinous fluid. Cytology of the fluid reveals 4+ cocci, and you diagnose a deep bacterial pyoderma. You culture the lesion and start Clindamycin based on the culture results. The dog returns in four weeks for another recheck examination. No bacteria are found on cytology, and clinically the dog looks excellent. You repeat a skin scrape and find Demodex mites. You inform the owner to continue Ivermectin. What should you do regarding continuation of antibiotics?

a. Continue the antibiotics for another 2 weeks

b. Discontinue the antibiotics, since cytology was negative and the clinical signs have resolved

c. Continue the antibiotics until the demodex has resolved

d. Perform another culture and if positive keep treating; if negative discontinue antibiotics

a. Continue the antibiotics for another 2 weeks

Deep pyodermas involve tissues deeper than the epidermis including the dermis and even subcutis. Most often deep infections have resulted from an uncontrolled superficial infection. Deep lesions usually heal on the surface before the deeper infection is resolved; making clinical cure difficult to assess. Therefore, antibiotic treatment should be continued for 7-21 days after the tissues return to normal. In general, deep infections can require 6-8 weeks of antibiotic treatment and even 12 weeks for severe cases. Superficial infections require 3-4 weeks of antibiotic therapy or one week past clinical resolution.
Culture results will often be positive in normal dogs since normal dogs will have bacteria on their skin surface and in hair follicles. It is better to manage based on clinical signs. Cytology can miss deeper infections and it is better to extend antibiotic treatment even if cytology is negative.
It is not necessary to continue the antibiotics until resolution of demodicosis. Keep in mind that many Demodex patients will require several months of treatment. It is better to prevent recurrence of bacterial infections with topical therapy such as benzoyl peroxide shampoos.

11

Microsporum canis, Trichophyton mentagrophytes, and Microsporum gypseum are the three most common dermatophytes affecting dogs and cats. It is important to obtain fungal cultures and determine the species since the above species have different sources of infection. Knowing the source of the infection is critical to determining an appropriate treatment plan. Please match the following dermatophyte species with its primary source of infection.

a. Microsporum canis (dogs); Microsporum gypseum (plants), Trichophyton mentagrophytes (rodents)

b. Microsporum canis (cats); Microsporum gypseum (soil), Trichophyton mentagrophytes (soil)

c. Microsporum canis (cats); Microsporum gypseum (rodents), Trichophyton mentagrophytes (dogs)

d. Microsporum canis (dogs); Microsporum gypseum (soil), Trichophyton mentagrophytes (cats)

e. Microsporum canis (cats), Microsporum gypseum (soil), Trichophyton mentagrophytes (rodents)

e. Microsporum canis (cats), Microsporum gypseum (soil), Trichophyton mentagrophytes (rodents)

Microsporum gypseum is geophilic (meaning that it loves to grow in soil). This species often affects dogs that like to dig. Trichophyton mentagrophytes is zoophilic and usually rodents serve as the host; dogs such as hunting dogs or roaming cats are most commonly affected. Microsporum canis is most commonly contracted from cats. It is extremely important to know which species of dermatophyte is causing the infection in order to prevent re-exposure. For example, in dogs with Microsporum gypseum, preventing them digging in the yard is going to be an important part of the treatment plan.

12

A 5-year old male neutered German Shepherd presents with a history of nasal dermatitis. Previous treatment with a 2-week course of antibiotics and prednisone resulted in partial improvement of the lesions followed by recurrence. On physical examination, you see the lesions on the nasal planum and oral mucosa shown in the images.

You perform a biopsy, and histopathology shows clefts characterized by residual basal keratinocytes remaining attached to the basement membrane zone and having a "tombstone" appearance. The intact primary bullae are non-inflammatory, but there is mononuclear inflammation of the superficial dermis. IgG and complement deposition between keratinocytes at all levels of the epidermis is present. The histologic diagnosis is pemphigus vulgaris. Which of the following is appropriate information to give the client regarding the treatment AND prognosis for this condition?

a. Treatment with fluconazole and/or clotrimazole is recommended and the long-term prognosis is good for most dogs

b. 0.1-0.5 mg/kg of prednisolone twice daily with possible addition of azathioprine is recommended and the long-term prognosis is good for most dogs

c.  Treatment with 0.1-0.5 mg/kg of prednisolone twice daily with the possible addition of topical tacrolimus is recommended and the long-term prognosis is good for most dogs

d. 2-4 mg/kg of prednisolone twice daily with possible addition of azathioprine is recommended but the long-term prognosis is poor

e. 2-4 mg/kg of prednisolone and concurrent treatment with retinoids is recommended but the long-term prognosis is poor

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d. 2-4 mg/kg of prednisolone twice daily with possible addition of azathioprine is recommended but the long-term prognosis is poor

Pemphigus vulgaris is an autoimmune disorder causing vesicles, ulceration, and crusting. It can affect the whole body, but it especially affects the mucocutaneous junctions and oral mucosa. The onset of the disease can be sudden (acute) or gradual over many weeks (chronic).

The disorder is caused by an IgG autoantibody that binds to intracellular adhesion molecules (desmoglein) causing a loss of cohesion between keratinocytes resulting in acantholysis, vesicle formation, and eventually ulceration.

The treatment is immunosuppressive therapy with corticosteroids and frequently additional immunomodulatory or immunosuppressive drugs such as azathioprine, cyclophosphamide, chlorambucil, or others. Unfortunately, long-term therapy is generally required and these treatments cause serious side-effects long-term. Prognosis is poor and euthanasia is often performed.

13

A 5-month-old pit bull puppy presents for a small area of hair loss. The lesion is well-demarcated, and the dog is not pruritic. Upon examination, you notice mild crusting around the lesion. You perform skin cytology and no bacteria or yeast is observed. Skin scrape reveals a few cigar-shaped mites. What is your next step?

a. Initiate therapy with Ivermectin

b. Initiate therapy with Amitraz dips

c. Benign neglect and monitor the lesions

d. Initiate therapy with Lyme sulfur dips

c. Benign neglect and monitor the lesions

Localized, juvenile onset demodicosis usually resolves without treatment as the immune system develops. Because this patient only has a small area of alopecia and few mites, starting therapy with Ivermectin and Amitraz dips is pre-mature. Both these therapies have marked side effects. Ivermectin causes neurological signs, and Amitraz can cause allergic reactions, hypothermia, bradycardia, and hyperglycemia (especially in small puppies). Lyme sulfur dips are not effective against follicular Demodex mites (as found in dogs). Demodex gatoi is found in cats and is a superficial mite that can be treated with Lyme sulfur.

14

A 2-year-old neutered male greyhound presents for crusting along his ear pinnae and elbows. The owner also explains that the dog is intensely pruritic. The dog mainly lives indoors but is also let outside into the backyard. The owner lives on a large rural property that is heavily wooded. You perform cytology, which returns negative for bacteria and yeast. You are highly suspicious of Sarcoptes. Which of the following would be most useful to help in your diagnosis of Sarcoptic mange?

a. Pinnal-pedal reflex, clinical signs, superficial skin scrape

b. Deep skin scrape, pinnal-pedal reflex, clinical signs

c. Clinical signs, superficial skin scrape, trichogram

d. Histopathology, deep skin scrape, trichogram

e. Superficial skin scrape, histopathology, trichogram

a. Pinnal-pedal reflex, clinical signs, superficial skin scrape

A superficial skin scrape is most useful. A deep skin scrape is used for Demodex mites, which reside in the hair follicles. Superficial skin scraping is indicated for Sarcoptic mange, since this mite lives in the stratum corneum. Pinnal-pedal reflex can be positive in 70% of Sarcoptic mange infestation but can also be positive in any dog with pruritus. Clinical signs are helpful because Sarcoptes typically infects the non-haired portions of the skin such as the ear pinnae, elbows, hocks, and ventral abdomen. If the mite is not found on skin scraping and you have clinical signs indicative of Sarcoptes then a therapeutic trial is warranted. Keep in mind that in most cases you will not be able to find the mite.

A trichogram would not be indicated. This method can be used to diagnose dermatophytosis and sometimes Demodex. Histopathology will reveal a perivascular dermatitis that is non-specific. Rarely are the mites found on histopathology.

15

A 5 year old, male neutered, West Highland White Terrier presents for the skin lesions seen in the picture below. He has a history of lethargy and poor appetite. The lesions partially responded to antibiotics initially, but then began to progress again. You take a biopsy of the skin which shows cutaneous blastomycosis. What is the next most important diagnostic test?

a. Blastomyces antibody titer

b. Abdominal radiographs

c. Thoracic radiographs

d. Deep skin scraping

d. Blastomyces antigen test

Q image thumb

c. Thoracic radiographs

Blastomycosis is caused by a dimorphic fungus and generally occurs in the Missouri, Mississippi, Tennessee, and Ohio river valleys. Pulmonary involvement occurs in the majority of cases, so thoracic radiographs are an important step to staging the patient. Other organs that can be affected include the lymph nodes, eyes, bones, central nervous system, and urinary tract.

Abdominal radiographs are not very sensitive to detect involvement with internal organs. Abdominal ultrasound, if available, would be preferred over abdominal radiographs.

Antibody tests are neither sensitive nor specific and are not very useful once a diagnosis is already made.

16

What breed of dog develops a dermatosis that seems to be related to a relative Zinc deficiency?

a. Siberian Husky

b. Bull dog

c. Cocker Spaniels

d. Shetland Sheepdog

a. Siberian Husky

This syndrome has also been seen in Alaskan Malamutes. They develop a crusting skin disease referred to as Zinc Responsive Dermatosis, where there is scaling, crusting, and alopecic dermatitis most frequently around the eyes, ears, prepuce, scrotum and vulva.

Absolute dietary deficiency of Zinc is rare. Zinc responsive dermatosis is related to defective intestinal absorption of Zinc. Oral Zinc supplementation can bring rapid resolution in most patients.

17

A 5-year old West Highland White Terrier presents for seborrhea oleosa and pruritus. You perform skin scrapes and a cytology and diagnose Malassezia dermatitis. Which of the following is the best treatment option?

a. Ketoconazole

b. Cephalexin

c. Griseofulvin

d. Carprofen

e. Prednisone

 

a. Ketoconazole

This medication, along with other -azoles (fluconazole, itraconzole), are commonly prescribed treatments for Malassezia. Terbinafine is another antifungal medication that is becoming more popular for the treatment of Malassezia and dermatophytosis. Although, Griseofulvin is an antifungal it is not effective against Malassezia. Prednisone and carprofen may help with inflammation, but not clear the infection.

18

A 2-year old female spayed Dachshund presents for further evaluation as a result of a mass on the pinna noted by the owner. On physical exam, the only abnormality noted was this mass. Cytology is consistent with a histiocytoma. Which of the following is the most reasonable treatment option?

a. Chemotherapy using lomustine

b. Radiation therapy

c. Benign Neglect

d. Cryotherapy

e. Radical surgical excision

c. Benign Neglect

Histiocytomas are typically benign and will often present as a small, raised mass that may or may not be ulcerated. Fortunately, these masses usually regress on their own, and surgical or medical intervention is typically not necessary.

19

A 5-year old female Golden Retriever presents for lethargy, dark runny stool, and dehydration. Bloodwork from yesterday showed markedly elevated plasma endogenous ACTH levels, K+ = 6.2 (3.9-5.1 mEq/L), Na+ = 135 (142-152 mEq/L), BUN = 62 mg/dl (8-28 mg/dl). Long-term maintenance therapy for this patient should most likely include:

a. Supplementation with physiologic doses of prednisone

b. IV fluids and daily doses of IV dexamethasone sodium phosphate

c. Mineralcorticoid, glucocorticoid, and NaCl supplementation

d. Mineralcorticoid supplementation alone

 

c. Mineralcorticoid, glucocorticoid, and NaCl supplementation

This dog has hypoadrenocorticism which is usually a deficiency in both glucocorticoids and mineralocorticoids. Elevated endogenous plasma ACTH concentrations with hypoadrenocorticism means the disease is due to primary adrenocortical insufficiency and failure to produce both types of corticosteroids (as opposed to secondary adrenocortical insufficiency, when the pituitary does not produce sufficient ACTH). Maintenance treatment of this disease includes supplementation with mineralocorticoids (e.g. Fludrocortisone acetate), glucocorticoids (e.g. Prednisone), and sodium chloride in the diet. IV fluids and dexamethasone sodium phosphate is used in an acute crisis.

20

Which is not a consequence of insulin deficiency in diabetes mellitus in a dog?

a. Weight gain leading to obesity

b. Increased mobilization of fat

c. Increased hepatic gluconeogenesis

d. Impaired energy utilization

e. Hepatic lipidosis and ketosis

a. Weight gain leading to obesity

Insulin deficiency causes weight loss, not weight gain. An insulin-deficient dog is essentially starving the cells of its body. Its energy utilization is impaired because it can't import glucose into its cells. In response to the decreased energy in the body's cells, the liver upregulates gluconeogenesis and glycogenolysis, exacerbating the hyperglycemia. The mobilization of fat is increased to supply the body with an alternative energy source. As adipocytes are broken down, the resulting free fatty acids are imported to the liver where they are converted to energy, triglycerides (which are stored in the liver causing hepatic lipidosis), and ketones (causing ketosis).

21

Which of the following is true of canine hypothyroidism?

a. It more commonly occurs in older, large breed dogs

b. It causes a voracious appetitie leading to weight gain

c. It causes thinning and increased fragility of skin

d. It can cause calcinosis cutis

a. It more commonly occurs in older, large breed dogs

Canine hypothyroidism can cause many skin changes including hyperpigmentation, alopecia, pyoderma, and seborrhea, but thinning and increased fragility of the skin does not occur. This is more consistent with hyperadrenocorticism, or Cushing's disease. Calcinosis cutis is also a clinical sign of Cushing's disease. Weight gain does occur with hypothyroidism due to a slower metabolism. Affected animals usually do not have a voracious appetite.

22

A 7-year old female Standard Poodle presents to you for acute onset of vomiting and weakness after the owners returned from vacation. On physical exam, you estimate that the dog is 7% dehydrated, has a respiratory rate of 36 breaths per minute, heart rate of 44 beats per minute and temperature of 99 degrees F. You quickly attach ECG leads and expect to see which of the following abnormalities?

a. Ventricular tachycardia

b. Tall, narrow QRS complexes

c. No P waves

d. Inverted T waves

c. No P waves

Based on the history and the physical exam findings of dehydration and bradycardia, you should be concerned about hypoadrenocorticism. Hypoadrenocorticism patients are typically hyperkalemic. ECG abnormalities with hyperkalemia include wide, flat, or absent P waves, widened QRS complexes, tall spiking T waves, and bradycardia.

23

A 7-year old female spayed Golden Retriever that you suspect has Addison's disease has bloody diarrhea, inappetance, and is dehydrated. What should be your next step?

a. Give IV dexamethasone and subcutaneous fluids

b. Start aggressive IV fluid therapy and run chemistry panel

c. Give Lysodren

d. Run a chemistry panel and perform an abdominal ultrasound

b. Start aggressive IV fluid therapy and run chemistry panel

Addisonian patients often present in hypovolemic shock, so the first step to treating this dog is to restore vascular volume with IV fluids and to run a chemistry panel to check the extent of electrolyte abnormalities (hyponatremia, hyperkalemia, and elevated BUN). IV dexamethasone would not take precedence over restoring vascular volume, and subcutaneous fluid treatment is not aggressive enough for treatment of hypovolemia. Abdominal ultrasound would not be a priority in this case but could eventually be helpful in ruling in/out other differentials.

Lysodren is used for treating hyperadrenocorticism. One possible complication of Lysodren treatment is to make a dog Addisonian, which often causes the animal to present with the signs described as in the question.

24

A dog presents to you with suspected hyperadrenocorticism. You would like to try to diagnose and differentiate between pituitary dependent and adrenal dependent hyperadrenocorticism with one test. Which of the following tests for hyperadrenocorticism is primarily a screening test, but can also be a differentiating test?

a. ACTH stimulation test

b. High dose dexamethasone supression test

c. Endogenous ACTH level

d. Low dose dexamethasone suppression test

e. Urine cortisol:creatinine ratio

d. Low dose dexamethasone suppression test

The 8-hour post-dexamethasone sample is used to determine if the pet has hyperadrenocorticism. If the 8-hour sample is above 1.4 ug/dL, the test is diagnostic for hyperadrenocorticism (either pituitary dependent or adrenal dependent). If the 4-hour sample is below 1.4 ug/dL or less than half of the baseline value, it is diagnostic for pituitary dependent hyperadrenocorticism.

The urine cortisol:creatinine ratio is a screening test to rule out hyperadrenocorticism, if it is normal. The endogenous ACTH level and high dose dexamethasone suppression tests are differentiating tests only. An ACTH stimulation test is a screening test but cannot differentiate pituitary versus adrenal dependent hyperadrenocorticism.

25

A 5-year old male mixed breed dog presents with polyuria, polydipsia, polyphagia, and weight loss. The most likely diagnosis is ______.

a. Exocrine pancreatic insufficiency

b. Diabetes mellitus

c. Hyperadrenocorticism

d. Hypothyroidism

b. Diabetes mellitus

Diabetes mellitus is the most likely diagnosis of those listed above. The 4 classic signs of DM are PU, PD, PP, and weight loss.

EPI patients have PP and weight loss but are not PU and PD. Hyperadrenocorticism patients have PU, PD, and PP, but do not lose weight. None of the clinical signs described are consistent with hypothyroidism in a dog.

26

Which is not a consequence of insulin deficiency in diabetes mellitus in a dog?

a. Weight gain leading to obesity

b. Impaired energy utilization

c. Hepatic lipidosis and ketosis

d. Increased hepatic gluconeogenesis

e. Increased mobilization of fat

a. Weight gain leading to obesity

Insulin deficiency causes weight loss, not weight gain. An insulin-deficient dog is essentially starving the cells of its body. Its energy utilization is impaired because it can't import glucose into its cells. In response to the decreased energy in the body's cells, the liver upregulates gluconeogenesis and glycogenolysis, exacerbating the hyperglycemia. The mobilization of fat is increased to supply the body with an alternative energy source. As adipocytes are broken down, the resulting free fatty acids are imported to the liver where they are converted to energy, triglycerides (which are stored in the liver causing hepatic lipidosis), and ketones (causing ketosis).

27

What is the primary goal in the initial treatment of diabetic ketoacidotic dogs?

a. Lowering the elevated blood glucose

b. Controlling obesity or concurrent disorders causing insulin resistance

c. Correction of acidosis, electrolyte abnormalities, and hyperosmolality

d. Getting the animal to eat

c. Correction of acidosis, electrolyte abnormalities, and hyperosmola

Initial treatment of DKA patients is aimed at correcting acidosis by administering bicarbonate (if the total bicarbonate is markedly low), correcting electrolyte abnormalities with IV fluids, potassium and phosphorus supplementation, and correction of hyperosmolality. Regulating blood glucose, getting the animal to eat, controlling obesity and concurrent disease should be addressed after immediate life-threatening issues are resolved.

28

A 7-year old, male, castrated shepherd mix presents for polyuria and polydipsia. The physical exam reveals a body condition score of 4/9 and 5% dehydration. The urine specific gravity is 1.006. The urinalysis, chemistry panel, and CBC are otherwise unremarkable. Which of the following is the most likely diagnosis?

a. Central diabetes insipidus

b. Fanconi syndrome

c. Chronic renal failure

d. Diabetes mellitus

 

a. Central diabetes insipidus

Diabetes mellitus is ruled out with a normal blood glucose on the chemistry panel and lack of glucose in the urine on the urinalysis. Chronic renal failure is ruled out because there is no azotemia on the chemistry panel. Fanconi syndrome usually occurs in Basenjis and is ruled out because there is no glucose in the urine.

29

A 9-year old male, neutered German Shepherd dog is presented to your clinic for evaluation of tenesmus, tail chasing, and hematochezia. Malodorous mucopurulent discharge is noted near his anus. On examination, you find multiple ulcerations around his perineum. Rectal examination reveals reduced anal tone and mucosal thickening. What are your treatment recommendations for this dog?

a. Initiate therapy with metronidazole

b. Initiate chemotherapy with the alkylating agent, melphalan, as this is the treatment of choice for anal sac adenocarcinoma

c. Initiate therapy with cyclosporine

d. Initiate broad-spectrum antibiotics to treat for an infected anal gland abscess

e. Surgically correct with a 360-degree anoplasty

c. Initiate therapy with cyclosporine

The signalment, history and clinical signs are most consistent with a perianal fistula. Although the pathogenesis is not fully understood, this disease is thought to be primarily immune-mediated. The treatment of choice for perianal fistula is medical management with cyclosporine, as resolution is achieved in greater than 65% of dogs. Surgical correction may lead to fecal incontinence or stricture formation, however surgery for removal of the anal sacs in combination with cyclosporine has recently shown promise.

If this was an anal gland abscess, lancing the abscess and drain placement with systemic antimicrobial therapy would be indicated. If you suspected this to be a cancerous process, a minimum database including CBC, chemistry, thoracic radiographs and abdominal ultrasound are recommended for disease staging. The treatment of choice for anal sac adenocarcinoma is surgical resection, followed by adjunct therapy.

30

Which of these is an adrenergic vasopressor in dogs?

a. Glycopyrrolate

b. Dopamine

c. Atropine

d. Hydralazine

b. Dopamine

Adrenergic vasopressors are frequently used to treat hypotension during anesthesia. Drugs in this category are dopamine, dobutamine, ephedrine, phenylephrine, and norepinephrine. Atropine and glycopyrrolate are anticholinergic drugs. Hydralazine is a vasodilator used to treat hypertension.

31

A 7-month-old miniature Schnauzer is presented with a history of straining to urinate.  Which one of the following choices is the most likely diagnosis based on the post-contrast study?

a. Urethral tear

b. Urethral stricture

c. Normal radiographs

d. Cystic wall mass

e. Cystic calculi

Q image thumb

b. Urethral stricture

This puppy has a urethral stricture.

There are no abnormalities involving the abdomen or urinary tract on the pre-contrast lateral radiograph.  A contrast urethrogram was performed.

A Foley catheter was placed in the distal urethra and the balloon inflated.  Non-ionic contrast medium was injected, and several radiographs were taken during this procedure.

There is a focal narrowing of the urethra 1cm caudal to the os penis.  This narrowed area is visible on contrast projections.

Urethral strictures may form secondary to trauma or lodged calculi.  The normal urethral narrows through the pelvis, then widens slightly at the prostate gland.

True narrowing or filling defects should be visible on multiple images.  Air bubbles can mimic filling defects but will move to different locations in the urethra as contrast is injected

32

A vaccinated Pomeranian dog arrives at your clinic after biting a human. What should happen to the dog?

a. Confine the dog and observe it for 10 days

b. Euthanize the dog and test for rabies

c. Vaccinate the dog immediately and quarantine for 10 days

d. Vaccinate the dog immediately and quarantine for 45 days

e. Vaccinate the dog after 6 month quarantine

a. Confine the dog and observe it for 10 days

With a healthy, vaccinated dog, the 10 day confinement period can be carried out in the owner's home. You would only need to euthanize and test if the dog is an unvaccinated stray. If the dog was not up-to-date on vaccinations, you would either euthanize and test or quarantine for 10 days in an approved facility.

The answer choice to vaccinate the dog immediately and quarantine for 45 days would be recommended if the dog were bitten by an animal that was rabid or suspected to be rabid.

33

Which of the fungal infections is considered contagious, either to other animals or to man (zoonotic)?

a. Sporptrichosis

b. Cryptococcosis

c. Aspergillosis

d. Coccidioidomycosis

e. Blastomycosis

a. Sporptrichosis

All of these fungal diseases can infect both animals and people. However, they are not considered contagious (not to be confused with infectious) with the exception of Sporothrix. This is because they are mainly acquired from the environment, and transmission from animal to animal is rare. Sporothrix, especially in cats, is a high risk to veterinarians and care should be taken to limit contact with exudates and lesions in cats.

Aspergillus is generally considered a ubiquitous fungus that causes infection due to host factors such as immunosucceptibility or certain breed predilections. Cryptococcus is also not a contagious disease (do NOT confuse this with cryptosporidium, which is very contagious and zoonotic as several of my colleagues can attest to profusely). Cryptococcus infection occurs from inhalation of the yeast from the environment, frequently avian habitats, as it survives ideally in pigeon droppings. Essentially, histoplasma, blastomyces, and Coccidioides are also all environmental diseases as well and not considered contagious.

Incidentally, there is a true story of a pathologist who did acquire Coccidioides from an animal that was having a necropsy. It is likely that the fungus reverted to the mycelial phase and produced infectious arthroconidia at the low temperatures achieved in the dead animal. This is also a risk when changing bandages for the same reason. These fungi are also potentially infectious when they are being grown on culture plates. So even though they are not technically contagious (at least in terms of how the board examiners view them), there are still risks.

34

Which of these drugs can cause aplastic anemia in humans?

a. Clindamycin

b. Neomycin

c. Chloramphenicol

d. Enrofloxacin

e. Sulfadiazine

c. Chloramphenicol

Even though this is a human question, this is something you do need to know for board exams. This potential side effect of chloramphenicol is why it is not allowed for use in food animals and that it is used with caution in companion animals. The person administering this drug should take precautions to avoid coming into contact with it.

35

Zoonotic diseases commonly carried by raccoons include rabies and ____________.

a. Trichinella

b. Toxocara

c. Echinococcus

d. Baylisascaris

d. Baylisascaris

Baylisascaris procyonis is an ascarid parasite of raccoons that causes mild signs in raccoons but can undergo aberrant migration in humans and cause fatal central nervous system signs.

36

A 2-year old Siberian Husky presents for crusting and scaling of his foot bads, periorbitally, and along his mucocutaneous junctions.  Based on the breed and clinical signs, which supplement should be added to this dog's diet?

a. Copper

b. Zinc

c. Vitamin E

d. Calcium

b. Zinc

Huskies are predisposed to zinc-responsive dermatosis in which individuals have a higher requirement for zinc in their diets due to a defect in abdorption of the element.  Clinical signs include crusting and scaling of foot bads, elbows, eyes, and mucocutaneous junctions.

37

You are examining a dog for lameness and on radiographs; tiy fubd gtoertrophic osteopathy of the metacarpal bones.  What is the likely cause of this lesion?

a. Pulmonary neoplasia

b. Ca deficiency

c. Vitamin D deficiency

d. Bone tumor

e. Trauma

a. Pulmonary neoplasia

Hypertrophic osteopathy is visible as periosteal proliferation in the diaphyses of affected bones.  Usually the metacarpal and metatarsal bones are affected first, and it may progress to the long bones.  Lameness, pain, and swelling are usually evident.  Joints are unaffected.  The cause is usually primary or metastatic pulmonary neoplasia, although other diseases in the thorax including bronchopneumonia, Spirocerca infection, or congestive heart failure, may also be associated.  Less commonly, abdominal neoplasia may be seen with this lesion

38

a 6-year old male castrated Borzoi dog presnts to you with a one-year history of polyuria and polydipsia with no other clinical signs.  A urinalysis confirms a specific gravity of 1.003 and no other abdnormalities

Serum chemistry shows:

Ca 10.1mg/dL (9.1-11.7mg/dL)

P: 3.2 mg/dL (2.9-5.3 mg/dL) 

Bilirubin:  0.1mg/dL ((0.0-0.3mg/dL)

Albumin:  2.9g/dL (2.3-3.1 g/dL)

Globulin:  2.5 g/dL (2.7-4.4 g/dL)

ALT:  40 u/L (10-109 u/L)

Glucose:  104mg/dL (76-119mg/dL)

BUN:  8 mg/dL (8-28 mg/dL) 

Creatinine:  0.6 mg/dL (0.5-1.7 mg/dL)

Cholesterol 120 mg/dL (135-278 mg/dL)

You tentatively diagnose central diabetes insipidus and elect to try the dog on desmopression (DDAVP) to see if the PU/PD resolves.  Which of the following reasons best explains why you might not see a response the first 24-48 hours, even if your diagnosis is correct?

a. It takes a few days for the hypothalamus to respond to DDAVP and to start making antidiuretic hormone (ADH)

b. It may take up to 3 days to overcome medullary washout from being polyuric and polydipsic

c.  Trauma to the hypothalamus or pituitary causing CDI will never respond to antidiuretic hormone (ADH)

d.  It may take up to 3 days to reactivate the antidiuretic hormone (ADH) receptors in the kidneys

b. It may take up to 3 days to overcome medullary washout from being polyuric and polydipsic

DDAVP is a synthetic ADH used to replace the lacking endogenous hormone.  DDAVP does not induce the hypothalamus to make ADH.  Medullary washout commonly occurs with CDI from prolonged PU and PD>  It may take up 3 days to get the medullary sodium concentration and concentrating mechanisms back in order.  ADH receptors in the kidneys are not affected in CDI.

39

A domestic short hair cat presents for decreased appetite due to chronic renal disease.  Which of the following is an appropriate appetite stimulant?

a.  Omeprazole

b. Famotidine

c.  Metoclopramide

d.  Mirtazapine

e.  Maropitant

d.  Mirtazapine

Although, all of the options given can potentially help a cat with renal disease feel better, the only medication considered an appetite stimulant is mirtazapine.  Martazapine works by increasing norepinephrine in the system, which acts as an alpha-receptor agonist, causing an increase in appetitie.  It is also a serotonin receptor antagonist, which inhibits 5HT2 and 5HT3 receptors, so it acts as an anti-emetic as well.

Famotidine (Pepcid) is an H-2 receptor blocker while omeprazole (Prilosec) is a proton pump inhibitor.  Both reduce gastric acid secretion. 

Maropitant (Cerenia) is a neurokinin-1 inhibitor, which inhibits Substance P in the CNS

Metoclopramide is a prokinetic and anti-emetic drug.  The mechanism for its anti-emetic effects is from antagonism of dopamine at its receptors in the chemo-receptor trigger zone of the brain.

40

You perform a low-dose dexamethasone suppression test on a dog you suspect has Cushing's syndrome.  The 4-hour blood cortisol level and 8-hour blood cortisol level are approximately equially elevated above the normal range.  What can you conclude from this information?

a. The dog has iatrogenic Cushing's syndrome

b. The dog has a cortisol-secreting adrenal tumor

c. The dog has pituitary-dependent hyperadrenocorticism

d. A high-dose dexamethasone suppression test could help differentiate pituitary versus adrenal dependent hyperadrenocorticism

d. A high-dose dexamethasone suppression test could help differentiate pituitary versus adrenal dependent hyperadrenocorticism

The correct answer is you should run a high-dose dexamethasone suppression test.  Elevated blood cortisol concentration 4 hours and 8 hours post low- dose dexamethasone administration is diagnostic for hyperadrenocorticism, but it does not allow differentiation between PDH and a cortisol secreting adrenal tumor.  Dexamethasone is more rapidly metabolized in dogs with either type of hyperadrenocorticism (approximately 4 hours to metabolize as opposed to 30 hours in normal dogs).  In PDH animals, the 4-hour post-cortisol concentration may sometimes be suppressed, whereas cortisol from adrenal tumors will not be suppressed after administration of a low dose dexamethasone.  A high-dose dexamethasone test will suppress a larger percentage of PDH patients (up to 75% will be suppressed, showing a decrease in cortisol after 4 hours).  Less reliable test to differentiate PDH from an adrenal tumor include endogenous plasma ACTH concentration or abdominal ultrasound.

41

Which of these dietary recommendations is most appropriate to give to someone raising a large breed puppy?

a. Calcium levels in the diet do not play a factor in skeletal development

b. Calcium in the diet of large breed puppies is of less clinical importance than it is in small breeds.

c. It is important to limit calcium intake to prevent skeletal abnormalities

d. It is important to supplement calcium to prevent skeletal abnormalities

c. It is important to limit calcium intake to prevent skeletal abnormalities

In fast-growing, large-breed puppies, diets high in calcium have been shown to predispose them to osteochondrosis and retained cartilage cores.

42

Which of the following is the treatment of choice for Trichuris vulpis in dogs?

a. Fenbendazole

b. Ivermectin

c. Imidacloprid

d. Praziquantel

a. Fenbendazole

Trichuris vulpis is the canine whipworm.  It commonly inhabits the cecum and causes diarrhea, weight loss, or hematochezia in severe infections.  Light infections are subclinical.  Treatment is with fenbendazole or milbemycin oxime.

43

Which of these clinical findings would you expect in a case of lymphagiectasia in a Belgian sheepdog as depicted in the photo?

a. Hypercalcemia

b. Hypercholesterolemia

c. Panhypoproteinemia

d. Lymphocytosis

c. Panhypoproteinemia

Lymphagiectasia is a classic example of a protein-losing enteropathy.  It is characterized by dilation and dysfunction of intestinal lymphatics and leakage of protein-rich lymph into the intestinal lumen.  As a result, protein, cholesterol, and lymphocytes are all lost.  Calcium is also frequently low due to either low albumin or vitamin D and calcium malabsorption

44

Which of the following is a non-adrenergic vasoconstrictor that can be used in dogs?

a. Epinephrine

b. Dobutamine

c. Phenylephrine

d. Vasopressin

e. Isoproterenol

d. Vasopressin

Epinephrine and phenylephrine are adrenergic vasoconstrictors.  Isoproterenol and dobutamine cause vasodilation.  Casopression (also known as anti-diuretic hormone) is a V-1 receptor, non-adrenergic, vasoconstrictor

 

45

A 8-year old male Doberman Pincher is being treated by your colleague for dilated cardiomyopathy.  You hear an arrhythmia on exam and record the following ECG.  What is your diagnosis?

a. Atrial premature complexes

b. Atrial fibrillation

c. Sinus arrhythmia

d. Normal sinus rhythm

e. Second degree AV block

b. Atrial fibrillation

Although the rate is not fast, there are no discernible P waves and the R-R interval varies with each beat.  This irregularly irregular rhythm is a hallmark of atrial fibrillation.  Normal sinus rhythm and sinus arrhythmia are incorrect as there are no P waves apparent.  Atrial premature complexes i wrong because the irregularity is from the fibrillation waves in the atria, not a discrete premature focus.  Second degree heart block is not correct because no P waves are seen, as would be expected with intermittent block

46

This 8-year old female spayed Pug is being treated for ketatoconjunctivitis sicca without much success.  You suspecte this is a result of poor owner compliance with the medications you prescribed.  What is the most likely Schirmer tear test value?

a. 6mm/min

b. 15mm/min

c. 27mm/min

d. 22mm/min

a. 6mm/min

A normal Schirmer tear test is considered to be greater than 15mm/min.  A value between 10-15 mm/min is considwered marginal and may or may not be consistent with Keratoconjunctivitis Sicca (KCS), which is dry eye.  When diagnosing KCS it is important to have a good clinical picture, especially when the Schirmer tear test is in the gray area.

47

Which of the following can be used to reverse the effects of medetomidine?

a. Naloxone

b. Xylazine

c. Atropine

d. Atipamezole

d. Atipamezole

Medetomidine is an alpha 2 agonist sedative/analgesic often used for premedication to general anesthesia, chemical restraint, and for epidural anesthesia/analgesia.  Atipamezole is a potent alpha 2 antagonist that reverses the effects of alpha 2 agonists.  Other alpha 2 antagonists include yohimidine and tolazoline

48

A 4-year old female spayed breed dog presents for further evaluation.  She has a 24 hour history of increased respiratory rate and decreased appetitie.  Owners note that she is an inddor/outdoor dog.  Based on these radiographs.  What is the best treatment?

a. Left caudal lung mass removal

b. Pericardiocentesis

c. Intravenous furosemide

d. Thoracocentesis

d. Thoracocentesis

This patient has a left sided pneumothorax.  Pneumothorax can be secondary to trauma, ruptured bullae, infection, or neoplasia.  The radiograph shows an elevated heart off the sternum as well as collapse of the lung lobes.  Notice there are no bronchi or vessels extending caudally toward the diaphrgm due to collapse of the lung

 

Pericardiocentesis would be indicated if you had a very large globoid heartm suggestive of pericardial effusion.  The heart does not appear enlarged and there is no pulmonary edema making intravenous furosemide a poor choice.  Do not confuse a collapsed lung lobe for a lung mass

49

Which of these groups is considered predisposed to developing nasal aspergillosis?

a. Dogs in large groups or kennels

b. Hunting dogs

c. Brachycephalics

d. Immunocompromised dogs

e. Dolichocephalic

e. Dolichocephalic

Aspergillus is typically a disease of healthy, apparently immunocompetent dogs that are young to middle-aged.  Dolichocephalic breeds are overpresented.  Immunocompromise does predispose to development of disseminated aspergillosis.  Being in a large group of dogs does not increase risk, as it is not a contagious disease.  Aspergillus is fairly ubiquitous in the environment, and hunting dogs are probably not exposed significantly more than any other dogs

50

a 3-year old German Shepherd presents for multiple subcutaneous nodules on the right front limb that have been present for about one week.  The dog is otherwise healthy.  The owner states that the dog lives mostly outdoor in a wooded area with ponds in Florida.  You are highly suspicious of pythium; what is the best therapeutic option for this disease?

a. Prednisone

b. Ivermectine

c. Lufenuron

d. Antifungal therapy

e. Amputation and treatment with an antifungal

f. Amputation and treatment with doxycycline

e. Amputation and treatment with an antifungal

Pythium is an aquatic organism that inhabits ponds of the Southeast United States.  These organisms have different cell walls than regular fungi, which makes them difficult to treat since most antifungal treatments target fungal cell wall synthesis.  Prognosis is extremely poor with this disease and amputation (if the lesions are localized to an affected limb) is currently the best option.  Amputation should always be followed with multiple long-term antifungal therapies.  Owners should be warned that local postoperative recurrence is common.  Dogs are most commonly affected, but this disease can also occur in cats.  It has also been reported in humans and horses.

 

Doxycycline is an antibiotic and would not be effective for this disease.  Prednisone would be contraindicated for pythium.  Lufenuron is a chitin synthesis inhibitor used for flea control and would not be effective.  Ivermectin is an anti-parasite drug and would not be effective

51

A two-year oldDachshund presents for hairloss (see image).  He is not pruritic.  Both ears are affected.  No other hair loss is noted over the rest of his body.  His physical exam is unremarkable.  In house skin scrapings are negative for mites.  Blood work and thyroid levels are unremarkable.  What is the most likely cause?

a. Endocrine disorder

b. Mite infection

c. Bacterial infection

d. Immune-mediated

e. Breed related

e. Breed related

Canine pinnal alopecia is a form of pattern alopecia.  Pinnal alopecia is most commonly diagnosed in Dachshunds, but can be seen in Chihuahuas, Boston Terries, Bull Terries, Yorkshire Terriers, and Italian Greyhounds.  The condition usually occurs in dogs older than 1 year of age and results in slowly, progressive, bilateral pinnal alopecia.  The ear margins may become chronically hyperpigmented and thickened.  The condition is benign and requires no specific treatment.

Distribution of the alopecia is an important key to determining the underlying diagnosis.  It may help in distinguishing inflammatory from non-inflammatory causes, thus narrowing down your differential list.  Inflammation results in a patchy pattern of alopecia that is not symmetrically distributedl whereas, many of the noninflammatory alopecias have a symmetrical pattern of alopecia.  Hypothyroidism often causes alopecia of the tail and may also be associated with alopecia of the nose bridge.  Hair loss begins with the pinna at 6 to 9 months of age and may progress to complete pinnal alopecia.  Total body alopecia with pigmentation may occur with age.  Treatment with oral melatonin may cause hair regrowth with this and other pattern baldness syndromes.  Other medications that can be used with variable success are pentoxifylline and Omega 3 oils topically.

52

Which of these biochemical profiles are most consistent with the diagnosis of insulinoma in a dog?

a. Blood glucose = 150mg/dL, Serum insulin-low

b. Blood glucose =150 mg/dL, Serum insulin-high

c. Blood glucose = 45mg/dL, Serum insulin-high

d. Blood glucose = 45mg/dL, Serum insulin-low

c. Blood glucose = 45mg/dL, Serum insulin-high

An insulinoma can result in an animal having normal to high insulin levels in the face of low blood glucose levels because the normal controls of insulin secretion are lost

53

A dog presents to your clinic for coughing and fever a week after going hunting.  You work the dog up, perform bronchoscopy and remove a plant awan from the lungs.  What bacterial infection is this dog predisposed to?

a. Pasteurella multocida

b. Actinomyces

c. Staphylococcus pseudointermedius

d. Nocardia

e. Staphylococcus aureus

b. Actinomyces

This is a filamentous, branching, gram positive bacteria that is a normal inhabitant of the mouth and oropharynx.  It is commonly associated with grass awn migration.  These are usually contaminated in the oropharynx and the migrate through the body from the respiratory of GI tracts.  Many times it takes months to oyears to make a diagnosis.  Nocardia is a ubiquitous soil saprophyte found everywhere and is usually introduced via the respiratory tract.

54

A 4 year old female Collie presents to you for lethargy.  The owner reports she has been drinking more and urinating frequently.  She has also vomited several times.  Her temperature is 104F (40C).  An abdominal radiograph of the dog is shown below.  What is the most appropriate treatment plan for this dog?

a. Parenteral fluids and antibiotics

b. Emergency ovariohysterectomy

c. Adrenalectomy

d. Enterotomy or gastrointestinal resection-anastomosis

e. Administer IV calcium gluconate

f. Splenectomy

b. Emergency ovariohysterectomy

The history and radiograph are consistent with a diagnosis of puometra due to the presence of fluid-filled uterine loops in the caudal abdomen.  Pyometra can be managed medically in some cases with hormonal and antibiotic therapy but in most cases, the treatment of choice is ovariohysterectomy to remove the infected tissue and prevent future pyometra at subsequent heats.

55

A 10-year old Shih Tzu presents for collapse.  A diagnostic work up shows a mass on the right kidney, which was subsequently removed and biopsied as renal carcinoma.  Which one of the following can be associated with renal carcinoma?

a. Polycythemia

b. Hyperadrenocorticism

c. Hyperestrogenism

d. Thrombocytopathy

e. Hypercalcemia

a. Polycythemia

Renal carcinomas have been associated with erythropoietin secretion, causing elevations in hematocrit as a paraneoplastic syndrome.

Hypercalcemia is associated with anal sac adenocarcinomas, lymphomas and other tumors

Thrombocytopathy can be seen with hemangiosarcoma and multiplelyeloma

Hyperestrogenism can be seen with Sertoli cell tumors

56

a 1-year old femal spayed Pit Bull presents for a focal area of alopecia that is well circumscribed, erythematous, and scaling.  A deep skin scraping reveals Demodex mites.  Which of the following is true regarding treatment for demodicosis?

a. Treatment of localized Demodex in young dogs is usually unnecessary.  It usually clears up on its own

b. The dog should be separated from people and treated aggressively with topical agents like Goodwinol (rotenone) because the disease is zoonotic

c. Shampoos containing benzoyl peroxide should not be used in this patient

d. Ivermectin should be used in all patients with demodicosis

a. Treatment of localized Demodex in young dogs is usually unnecessary.  It usually clears up on its own

It usually clears up on its own.  Ivermectin is usually used to treat generalized Demodex and should not be used in heartworm positive animals and herding dogs like collies and Shepherds (remember that Ivermectin also kills turtles!).  Benzoyl peroxide shampoos should be used with demodicosis patients.  Although, benzoyl peroxide can not directly kill the mite it aids in follicular flushing.  Demodex is a species-specific mite and is not considered zoonotic.  Goodwinol is a topical agent sometimes used for localized demodicosis.

57

Which of the fungal infection is considered contagious, either to other animals or to man (zoonotic)?

a. Aspergillosis

b. Sporotrichosis

c. Coccidioidomycosis

d. Blastomycosis

e. Cryptococcosis

b. Sporotrichosis

All of these fungal diseases can infect both animals and people.  However, they are not considered contagious (not to be confused with infectious) with the exception of Sporothrix.  This is because they are mainly acquired from the environment, and transmission from animal to animal is rare.  Sporothrix, especially in cats, is a high risk to veterinarians and care should be taken to limit contact with exudates and lesions in cats.

Aspergillus is generally considered a ubiquitous fungus that causes infection due to host factors such as immunosucceptibility or certain breed predilections.  Cryptococcus is also not a contagious disease (do NOT conduse this with cryptosporidium, which is very contagious and zoonotic).  Cryptococcus infection occurs from inhalation of the yeast from the environment, frequently avian habitats, as it survives ideally in pigeon droppings.  Essentially, histoplasma, blastobyces, and Coccidioidesare also all environmental diseases as well and not considered contagious.

 

58

Which of these drugs can cause aplastic anemia in humans?

a. Clindamycin

b. Neomycin

c. Chloramphenicol

d. Enrofloxacin

e. Sulfadiazine

c. Chloramphenicol

Even though this is a human questions, this is something you do need to know for board exams.  This potential side effect of chloramphenicol is why it is not allowed for use in food animals and that it is used with caution in companion animals.  THe person administering this drug shold take precautions to avoid coming into contact with it.

59

What is the method of choice for diagnosing rabies?

a. Immunohistochemistry

b. RT-PCR

c. Gross pathologic lesions

d. Direct fluorescent antibody test

e. Visualization of Negri bodies

d. Direct fluorescent antibody test

There are no gross pathologic lesions associated with rabies.  A diagnostic microscopic lesion is the visualization of Negri bodies.  Most commonly they occur in the hippocampus in carnivores and Purkinje cells in herbivores.  However, these are only seen 50% of the time.  Immunohistochemistry allows strain differentiation and the ability to differentiate vaccine vs. wild-type.  RT-PCR has been used on autolyzed brain tissue that is difficult to evaluate with fluorescent antibodies, but this is not the test of choice at this time.  Direct FA is the current preferred method of diagnosis; it is both rapid and sensitive.  Usuallyimpression of the medulla, cerebellum, and hippocampus are performed.

60

How much protein should you feed a dog with hepatic insufficiency or hepatic encephalopathy?

a. The maximum amount of protein they will tolerate without causing signs of encephalopathy

b. The minimum amount of protein they will tolerate without developing hypoproteinemia

c. The toal quantity of protein is not important as long as they eat predominantly meat proteins rather than dairy proteins

d. 1.0 gram protein/kg/day

a. The maximum amount of protein they will tolerate without causing signs of encephalopathy

Dogs with hepatic insufficiency or hepatic encephalopathy need to have their protein levels restricted to reduce clinical signs associated with liver dysfunction; however, restricting protein intake to the point where hypoproteinemia develop is excessive.  If too little protein is fed to these patients, muscle catabolism may occur.  PRoteins derived from meat sources are more prone to causing encephalopathy than proteins from dairy sources due to the high levels of nucleic acids and other nitrogenous compounds found in meat that are converted to ammonia

61

Which of the following organisms is best visualized under dark field microscopy?

a. Ehrlichia

b. Mycobacterium

c. RIckettsia

d. Aspergillus

e. Leptospira

e. Leptospira

The causative agent of leptospirosis is a gram negative organism that stains poorly, if at all.  Dark field microscopy is the best way to identify this organism.  Leptospira also grows very slowly.  There are 7 serovars out of over 220 that tend to cause disease in animals

62

Which of these is the best measure of liver function in the dog from a routine chemistry panel?

a. Alkaline phosphatase (ALP)

b. Alanine aminotransferase (ALT)

c. Creatinine

d. Blood urea nitrogen (BUN)

d. Blood urea nitrogen (BUN)

ALT and ALP are liver enzymes and can indicate ongoing damage to the liver or cholestasis but do not tell you anyting about liver function.  Creatinine is produced by muscle and cleared by the kidney so it tells you nothing about liver function.  Urea is produced by liver and is one measure of liver function; it will be low in cases of liver failure.  Other tests of liver function on a routine chemistry panel are cholesterol, glucose, bilirubin, and albumin.  Bile acids also test liver function, but are not on a routine chemistry panel.  It is important to realize that in cases of end-stage liver failure, the liver function parameters will be affected, while frequently, liver enzymes will be normal.

63

A 2.5-year old miniature Schnauzer presents for further evaluation as a result of stranguria.  Abdominal ultrasound identified uroliths and the dogwas taken to surgery for a cystotomy.  Stone analysis revealed urate staones.  You call the owners to inform them of the resutls and recommend which diagnostic test?

a. Creatinine kinase levels

b. ACTH stimulation test

c. Low dose dexamethasone suppression test

d. Pre- and post-prandial bile acids test

d. Pre- and post-prandial bile acids test

Urate stones in a small breed dog are usually secondary to a portosystemic shunt until proven otherwise.  A portsystemic shunt results in blood from the abdomen being shunted away from the liver and into the main circulation.  If shunted, the liver does not have an opportunity to detoxify the blood, which among other toxins, is very high in ammonia.  The excess ammonia is excreted bia the kidneys.  High levels of ammonia can result in formation of ammonium biurate crystals and ultimately stones.

An ACTH stimulation test is used to help diagnose hypoadrenocorticism and hyperadrenocorticism.  A low dose dexamethasone test is used to help diagnose hyperadrenocorticism.  Creatine kinase levels are evaluated when there is a suspected myopathy

64

A 1-year-old female spayed COrgi presents for a seizure.  At home , she vomited what appeared to be paint chips.  Peripheral blood cytology and a complete blood count showed 20 nucleated red blood cells/100 white blood cells, basophilic stippling, and neutrophilic leukocytosis (see image).  She received a dose of diazepam, which has controlled her seizures.  What is the treatment of choice?

a. N-acetylcysteine

b. D-penacillamine

c. Doxycycline

d. Ca-EDTA

Q image thumb

d. Ca-EDTA

This dog is showing signs of lead poisoning.  Clinical signs are primarily gastrointestinal and neurologic.  Animals are usually exposed in old buildings or areas of renovation where they have access to lead paint, old batteries, lead fishing weights, etc.  Old food and water dishes can also be a source if lead paint was used.  Lead blood levels can be measured; however, they do not necessarily correlate with severity of clinical signs.  Toxic blood levles are greater than 0.4 ppm.  Bloodwork can show an elevated number of nucleated RBCs without anemia.  Basophilic stippling is a classic finding with lead toxicity but not specific.  Ca-EDTA is the chelator used to treat lead poisoning.  Succimer can also be given orally.  D-penacillamine has been used to chelate lead, copper, iron and mercury.  It is used more commonly for copper toxicity.  N-acetylcysteine is used for acetaminophen toxicity and hepatotoxicity.  Basophilic stippling can sometimes confused with erythrocytic parasite for which doxycycline may be the treatment of choice.

65

The mean circulating life span of a white blood cell in a dog is approximately ________.

a. 48 hours

b. 120 minutes

c. 5-9 days

d. 5-9 hours

 

d. 5-9 hours

Platelets have a circulating half life of 5-7 days and red blood cells have an approximate life span of 110 days in dogs

NOTE:  The approximate life span of RBCs in other species ( in days) is as follows:  cats-to, cow-160, horse-145, pig-86, sheep-150

66

A 1-year old female spayed Doberman Pinscher has presented after being hit by a car.  Initial radiographs show mild contusions, and the patient appears to be otherwise stable.  A right mid-shaft long oblique femoral fracture has been identified.  Routine pre-operative blood work is unremarkable.  A buccal mucosal bleeding test (BMBT) is elevated at 6 minutes.  What will you administer prior to surgery?

a. Vitamin K

b. Whole blood transfusion

c. 1,25 dihydrocholecalciferol

d. Desmopressin acetate (DDAVP)

d. Desmopressin acetate (DDAVP)

Administration of desmopression results in release of von Willebrand factor, which will help this patient with clotting.  Given this dog's breed and elevated BMBT there is a very strong likelihood she is afflicted with von Willebrand's disease.  In Dobermans this results in an inability to form a clot.  This can be life threatening if the dog is taken to surgery.

A whole blood transfusion does not provide an adequate source of von Willebrand factor but may be necessary if the patient's bleeding cannot be controlled despite appropriate pre-operative measures.  1,25 dihydrocholecalciferol is the active form of vitamin D which aids intestinal resorption of calcium.  The BMBT does not assess factors 2, 7, 9, 10 and therefore vitamin K is not indicated. 

67

A 7-year old male neutered Gold Retriever presents for lethargy and pale mucous membranes.  A purple top (EDTA) tube of blood is drawn.  A blood smear is made and examined.  These is a moderate regenerative anemia with an increase in spherocytes.  Mild agglutination is suspected.   A Spherocytes are consistent with which disease condition? 

a. Iron deficiency

b. Cobalamine and folate deficiency

c. Grape and raisin toxicity

d. Immune mediated hemolytic anemia

 

d. Immune mediated hemolytic anemia

In immune mediated hemolytic anemia RBCs are coated with immunoglobulins and are then engulfed by macrophages.  As a result, the RBC will lose a portion of its cell membrane but not hemoglobin.  With the loss of part of the cell membrane, spherocytes appear smaller (without volume loss), no central pallow, and stain deeply red.

In iron deficiency, RBC will be hypochromic (less red) and smaller (microcytic) due to less volume. 

Cobalamin and folate are necessary for DNA synthesis.  Giant schnauzers have an inherited cobalamin malabsorption which results in macrocytes and ovalocytes in circulation.

Grape and raisin toxicity result in acute renal failure

68

A 2-year old male castrated Bull Mastiff with a history of travel in the west coast presents to your clinic for a chronic cough a recent development of lameness of his right hind limb.  On physical exam you notice a draining lesion over the lame region of the right hind limb.  You perform chest radiographs and see a diffuse bronchointerstitial pattern which is nodular in some regions.  You also identify filar lymphadenopathy.  You suspect that you know what you are dealing with and perform a broncho-alveolar lavage for cytology.  Just as you suspected, you see spherules.  What is your diagnosis?

a. Coccidioidomycosis

b. Aspergillosis

c. Histoplasmosis

d. Blastomycosis

e. Cryptococcus

a. Coccidioidomycosis

The travel history and clinical signs are consistent with this answer.  Additionally, finding spherules on cytology is pathognomonic for Coccidioidomycosis.  Prolonged antifungal treatment will be necessary.  Fluconazole is the treatment of choice.  Ketoconazole and itraconazole are good choices.  With blastomycosis you see broad based budding of the yeast.  With Cryptococcus neoforms you will see narrow-based budding.

69

The image below is from an aspirate taken through the soft palate from a mass in the nose of an 8-year old male neutered Rhodesian Ridgeback dog.  Choose the correct cell type of origin AND classification

a. Epithelial origin; carcinoma

b. Epithelial origin; sarcoma

c. Mesenchymal origin; sarcoma

d. Mesenchymal origin; carcinoma

e. Leukocyte origin; round cell tumor

f. Mesenchymal origin; round cell tumor

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a. Epithelial origin; carcinoma

This is a nasal adenocarcinoma.  The classification scheme for tumors by cell of origin and cytologic description is:

Carcinoma - These tumors come from epithelial cells including cells of glandular tissues, such as salivary glands, mammary glands, and cells lining most tissues including squamous cells and transitional cells.  The cytologic appearance is that of COHESIVE CLUSTERS of cells.  Here, you can see some of the tight cellular junctions in the cluster which is typical.  Cells are often polygonal in shape.

Sarcoma - These tumors come from mesenchymal cells and are named by the specific cell type such as fibroblasts (fibrosarcoma) and osteoblasts (osteosarcoma).  Cytologically, they tend to appear as isolated spindle-shaped cell with elongated cytoplasm and often oval nuclei.

Round cell tumors - These are 5 round cell tumors and most but not all come from blood cells.  They are lymphoma, mast cell tumors, plasma cell tumors, histiocytic tumors, and transmissible venereal tumors.  Remember, these are also sometimes also referred to as sarcomas (i.e. lymphosarcoma or histiocytic sarcoma).  Cytologically, they appear usually as large populations of cells that are not in defined clusters.  The cells have a round shape, often with unique identifiable features such as the purple granules in mast cell tumors

70

A 1 yr 2 mo old Great Dane presents for further evaluation of persistent lameness of the right hind limb.  Previously he had been seen by your associate who had recommended radiographs in an attempt to localize the pain since the orthopedic exam was unrewarding.  The patient was sent home on carprofen for 2 weeks which helped a little.  He is here today for a recheck and tadiographs because he is just nogetting better according to the owner.  What will you tell the owner based on the radiographic findings?

a. Your dog is affected with panosteitis and we need to continue to treat medically.  His prognosis is ultimately excellent

b. There are no significant findings on the radiograph.  I recommend a lateral projection to be more complete

c. Your dog may be affected with juvenile onset osteosarcoma and we should perform a bone biopsy to rule this in or out

d. I'm concerned your dog may have hip dysplasia and would like to perform a distraction view to determine his distraction index

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a. Your dog is affected with panosteitis and we need to continue to treat medically.  His prognosis is ultimately excellent

The radiographs show a patchy opaque region within the medullary canal that might be described as slightly mottled when compared to the left side.  One can appreciate this from the lesser trochanter and distal half-way down the femur.  There is no evidence of cortical thinning or overt lysis suggestive of a neoplasitc process.  If the veterinarian were to palpate this region, it would be very painful to the patient.

The cause of panosteitis is currently unknown, but it is thankfully self-limiting and generally only affects dogs less than 2 years of age.  German shepherds tend to be predisposed.  Treatment is supportive with NSAIDs.  Owners are warned that their dog could develop panosteitis in other limbs as well.

The hips do not have any overt signs of degenerative changes suggesting hip dysplasia.  If the veterinarian were to sedate the patient, it would be prident to check for Ortolani to be on the safe side.

71

A 10 year old female spayed mixed breed dog presents for further evaluation of progressivelameness in the hind.  The owner notes that she has begun intermittently scuffing her hind limbs, has somewhat of a weak or drunken gait in the hind as she walks, and is having trouble rising.  Given the answer choices below, what is the best treatment?

a. Prolonged antibiotic therapy with clindamycin

b. Dorsal laminectomy

c. Total hip replacement bilaterally

d. Removal of the right TPLO plate

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b. Dorsal laminectomy

This patient's clinical signs are consistent with neurological deficits.  Although you do not have all of the information necessary to reach a definitive diagnosis, you should have been able to deduce that this patient probably needs a dorsal laminectomy to relieve disc compression.

In order to definitively diagnose the condition, you would want to proceed with a complete exam, basic bloodwork, and a CT or MRI of the lumbosacral region.  Although this patient does exhibit evidence of hip dysplasia radiographically, the clinical signs are not characteristic of a dog with pain secondary to hip dysplasia.  There is no indication of osteomyelitis on these radiographs and the clinical signs are not necessarily suggestive of osteomyelitis.  Removing the TPLO plate might be tempting if you identified a broken screw (proximal screw of the right tibia).  However, this broken screw is likely an incidental finding and does not cause the patient any discomfort since the TPLO site appears to be healed.

It is important not to skip ahead to image interpretation without carefully reading the question.  Doing so in this case would likely lead you to select the incorrect answer.

72

A 1-year-old male neutered Chihuahua presents for a 3 month history of intermittent limping and non-weight bearing on the left hind limb.  On physical exam, it is difficult to determine the source of pain as the paitnet seems to try to bite on any manipulation of the left hind limb.  The patient was sedated and these radiographs were obtained.  WHat is your diagnosis and treatment?

a. Left hip septic arthritis.  Perform joint culture and begin appropriate antibiotic therapy

b. Left hip dysplasia.  Perform femoral head and neck ostectomy or total hip replacement

c. Avascular necrosis of the femoral head.  Perform femoral head and neck ostectomy or total hip replacement

d. Left patellar luxation.  Perform trochlear wedge recession with tibial tuberosity transposition

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c. Avascular necrosis of the femoral head.  Perform femoral head and neck ostectomy or total hip replacement

Based on the breed and age of the patient, avascular necrosis of the femoral head should immediately be the top differential.  This condition is also known as Legg-Calves-Perthes disease and results in a collapse or fragmentation of the femoral epiphysis (as seen on the radiographs) because of a disruption in blood flow.  The cause of blood flow interruption is unknown.  The condition occurs in young small-breed dogs prior to closure of the capital femoral physis.  The condition can be seen bilaterally in 10-17% of patients.  Dogs are usually 6-7months of age when they first start showing clinical signs, but the age may range from 3-13 months.  Treatment with a femoral head and neck ostectomy (FHO) generally yields excellent results.  Alternatively, if owners demand perfect biomechanics, a total hip replacement may be considered, but most veterinarians tend to recommend an FHO.

     Radiographs will typically show a shortening of the femoral neck as well as osteochondrosis with chronicity, as appreciated in this patient.  Note the significant muscle atrophy of the patient's left limb as compared to the right.  Patellar luxation should always be a differential in any small breed dog and this should be ruled out via palpation since the patient may not necessarily be luxated at the time the radiograph was taken.  The patient's patellas are in a normal position in this radiograph.

     Septic arthritis of the femoral head is an uncommon condition which is more often seen in large-breed dogs with a history of degenerative joint disease of the hips.  They present with acute lameness, severe hip pain, and are usually febrile.  Radiographs usually show degenerative joint disease along with potentially lytic areas associated with the femoral head.  Neoplasia should also be considered in these cases.

     Small-breed dogs are less likely to have hip dysplasia as compared to large-breed dogs and should be kept as a lower differential

73

What is the recommended surgical treatment for canine patients with laryngeal paralysis?

a.  Soft palate resection

b. Unilateral artenoid lateralization

c. Resection of the laryngeal saccules

d. Partial laryngectomy

 

b. Unilateral artenoid lateralization

Resection of the soft palate is performed when dogs have respiratory problems as a result of having elongated soft palate.  Resection of the laryngeal saccules is performed when they are everted and causing resrpiatory distress.  A partial laryngectomy is performed in cases where there may be a mass or tumor to be removed.

74

Of the options below, which would be the best material to close this incision?

a. Ethilon

b. Catgut

c. Vicryl

d. Polydioxanone

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d. Polydioxanone

This suture material is absorbable and monofilament.  Polydioxanone (PDS) is broken down by hydrolysis and will last longer than catgut, which is better when working with the bladder.  On the other hand, you do not want a non-absorbable material as this predisposes the patient to urinary tract infections as a result of the permanent presence of foreign material.  Vicryl is a multifilament suture which also has a higher likelihood of failing due to the ability of bacteria to lodge in between the filaments.

75

15-25% of diaphragmatic hernias are not diagnosed until several weeks after trauma; therefore, it is important to perform thoracic radiographs in all animals that undergo significant trauma to avoid having an animal later go into respiratory distress and die.  How should you treat a diaphragmatic hernia as shown below?

a. Fascia lata graft using a simple interrupted pattern

b. Mesh graft using porcine small intestinal submucosa

c. Simple continuous pattern of an absorbable suture, such as polydioxanone

d. This hernia is too large and has exceeded the repair limits; the patient should be humanely euthanized

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c. Simple continuous pattern of an absorbable suture, such as polydioxanone

Acute, traumatic, diaphragmatic hernias should be repaired primarily without the use of any "substitute" material for the diaphragm to reduce the risk of complications.  It is very rare to have insufficient tissue/muscle to close an acute defect to the diaphragm.  Using the native diaphragmatic wall decreases the risk of failure because this technique involves tissue with a direct blood supply as opposed to a mesh type material that is foreign to the body.

76

The following image shows a 3-D CT reconstruction of a 7-year old mixed breed small dog with a history of pain on opening the mouth for the past 2 weeks. The patient initially received a dental prophylaxis and cleaning under the assumption that the pain was related to moderate dental disease. When the pain persisted skull radiographs were performed and showed evidence of a mixed proliferative and lytic mass at the proximal aspect of the vertical ramus. What muscle attaches to this region?

a. Pterygoid

b. Temporalis

c. Digastricus

d. Masseter

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b. Temporalis

The mass depicted in this three dimensional CT reconstruction involves the coronoid process. The ramus of the mandible consists of three distinct processes, the most dorsal being the coronoid process. It projects into the temporal fossa and provides an area for attachment of the temporalis muscle. The condylar (or condyloid) process is just ventral and slightly caudal to the coronoid process. This process is a point of articulation between the maxilla (retroarticular process) and mandible. Disruption of this region will result in temporomandibular joint luxation. The most ventral process is the angular process. This structure provides an area for attachment of the digastricus muscle. The masseter muscle inserts laterally on the mandible, while the pterygoid muscle inserts medially. The masseter, pterygoid, and temporalis muscles function to close the mouth while the digastricus opens the mouth.

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77

Dutchess, a five year old female spayed Labrador Retriever, presents to the emergency clinic with a 2 day history of lethargy, inappetance, diarrhea, and vomiting. On physical exam, she is painful on abdominal palpation, 7% dehydrated, and febrile.

Abdominal radiographs were performed and showed evidence of ascites and gas distension in the small intestines. Preliminary blood work showed a PCV of 32% (35-57 %), TP 2.2 g/dl (5.4-7.5 mg/dl), glucose 57 mg/dl (76-119 mg/dl), Na 140 mEq/L (142-152 mEq/L), Cl 115 mEq/L (110-124 mEq/L), K 3.9 mEq/L (3.9-5.1 mEq/L). Given the surgical findings (see image below) what is the likely abdominal fluid glucose level?

a.  At least 20 mg/dL greater than the blood glucose

b.  At least 10 mg/dL greater than the blood glucose

c.  At least 20 mg/dL less than the blood glucose

d.  At least 10 mg/dL less than the blood glucose

e.  Approximately the same as the blood glucose

c.  At least 20 mg/dL less than the blood glucose

The correct answer is at least 20 mg/dL less than the blood glucose. The image depicts a perforated colon, which will result in a septic abdomen due to the normal colonic flora emptying into the abdomen. A concentration difference > 20 mg/dL between blood and peritoneal fluid glucose concentration provides a rapid and reliable means to differentiate a septic peritoneal effusion from a nonseptic peritoneal effusion in dogs and cats.

78

Attached are x-rays of a 4-year old 63 pound German Shepherd mix. She presented yesterday with toe touching mixed with non-weight bearing continuing for the past 5 days. She was therapeutically started on Tramadol, Previcox and acepromazine as this pet is very active and hard to keep still. On the basis of the signalment and radiographic findings. What clinical exam finding would you expect to find and on which limb?

a. This patient is expected to have bone pain on palpation of the distal femur on the right hind limb

b. This patient is expected to have patellar luxation of the left hind limb

c. This patient is expected to have tibial thrust on the right hind limb

d. This patient is expected to have cranial drawer on the left hind limb

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d. This patient is expected to have cranial drawer on the left hind limb

Based on the radiographic finding of marked stifle effusion of the left stifle noted by the displacement of the infrapatellar fat pad (cloudy area as compared to right stifle) this patient likely has a cranial cruciate ligament rupture. The history and signalment help you to arrive at this top differential.

Other differentials such as immune mediated polyarthritis or joint infection would be ruled out after a thorough orthopedic exam. During this exam one can expect to find tibial thrust, cranial drawer, and pain on extension of the stifle.

Cranial cruciate ligament injuries are the most common orthopedic problem seen in dogs and should be a high differential for any large breed, active dog, with an acute history of lameness. Patellar luxation is relatively uncommon in large breed dogs and would be a very low differential. The right stifle radiograph has no effusion associated with the joint but does show some boney changes that are likely incidental, perhaps from prior trauma, at the distal aspect of the patella.

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79

An 8-month old Labrador Retriever mix presents for further evaluation of limping in the right hindlimb after running, for approximately 6 weeks duration. On physical exam pain is localized to the tarsus. The owner consented to radiographs of both tarsi. Based on the findings, what will you tell the owner?

a. Your dog likely has ligamentous damage given the amount of changes and I recommend a splint application for 6 weeks with weekly splint changes

b. Your dog likely has osteochondrosis dissecans of the medial trochlear ridge and removal of the flap and curretage is recommended

c. Your dog likely has a fragmented medial trochlear ridge and needs arthroscopic removal of the fragment

d. Your dog likely has a joint infection given the degree of radiographically visible swelling and I recommend a joint tap

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b. Your dog likely has osteochondrosis dissecans of the medial trochlear ridge and removal of the flap and curretage is recommended

The radiographs show evidence of effusion when compared to the contralateral limb. There is also a widened joint space of on the medial aspect at the level of the tibio-tarsal joint with flattening of the medial trochlear ridge. Those specific findings are highly suggestive of osteochondrosis dissecans (OCD). The signalment of the patient also fits with this diagnosis.

Young dogs are not typically affected by fragmentation of the medial trochlear ridge. If you selected this answer you are probably confusing yourself with a fragmented medial coronoid process which is a component of elbow dysplasia.

A joint infection of six weeks duration is highly unlikely and we would expect the dog to be more clinical if it was present for that length of time. Lethargy, inappetance, and pyrexia would be expected. The radiographic findings would probably show severe degenerative changes if it were ongoing for six weeks.

A ligamentous injury cannot be ruled out on this radiograph alone. Stress radiographs would be necessary to see if there is excessive laxity of the joint. If the findings consistent with OCD were not present, offering the owners stress radiographs as the next step would be reasonable.

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80

A dog presents to your clinic with tenesmus and swelling near the anus as seen in the image. On examination, there is a fluctuant swelling lateral to the anus, and on rectal exam, you note lateral dilatation of the rectum. Which of the following is the most common signalment for dogs presenting with this problem?

a. They are younger intact males

b. There is no age or sex predilection

c. They are older intact females

d. They are older intact males

e. They are younger intact females

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d. They are older intact males

This is a case of a perineal hernia. Older intact male dogs are most commonly affected. Overrepresented breeds include Boxers, Collies, Kelpies, Pekingese, and Boston terriers. The hernia results from a weakened pelvic diaphragm. It is thought that there may be a hormonal component which results in weakening with time.

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81

A 5-month old male Shar-pei presents for further evaluation of persistent regurgitation. There is no history of trauma or recent anesthesia. The dog is thin and has a ravenous appetite. Your differentials include persistent right aortic arch, idiopathic megaesophagus, and hiatal hernia. After imaging with fluoroscopy you confirm the diagnosis of hiatal hernia. Which of the following is best treatment choice?

a. Placement of esophagostomy tube until skeletal maturity is reached

b. Plication of the small intestines

c. Esophagopexy in conjunction with a left-sided gastropexy

d. Euthanasia due to grave prognosis

e. Esophageal resection and anastomosis of affected region

c. Esophagopexy in conjunction with a left-sided gastropexy

Performing these will help prevent the esophagus from herniating back into the thoracic cavity. The left-sided gastropexy increases the barrier pressure at the gastroesophageal junction. Resection and anastomosis of any region of the esophagus is associated with significant morbidity and mortality and should be avoided if possible. Additionally this does not necessarily address the problem. Placement of an esophagostomy tube does not fix any problems. Perhaps if medical management is pursued, a gastrostomy tube or jejunostomy tube is more appropriate. Plication of the small intestines was previously performed in animals that had intestinal intussusceptions and later found to not be substantially beneficial.

82

Which of the following is not a treatment option for a ruptured cranial cruciate ligament for a dog?

a. Recession trochleoplasty

b. Weight reduction

c. Leveling of the tibial plateau

d. Cranial transposition of the fibular head

 

a. Recession trochleoplasty

This technique is part of a surgical repair method for luxating patellas. Weight reduction is nearly always a therapeutic component to managing orthopedic disease. Leveling of the tibial plateau and cranial transposition of the fibular head are two surgical options for correcting a torn cranial cruciate ligament.

83

A 2-year old Golden Retriever presents to you after jumping from a height of 15 feet and sustaining a severe carpal hyperextension injury in his right carpus. The treatment of choice for this dog is _________.

a. Cast for 6-8 weeks

b. Splint and cage rest for 3 weeks

c. Non-steroidal anti-inflammatory drugs and cage rest for 3 weeks

d. Carpal ardesis

d. Carpal ardesis

Arthrodesis is the treatment of choice for severe hyperextension injuries to the carpus. This procedure is accomplished by debridement of the articular cartilage of the joints, implantation of a cancellous autograft into the debrided joint spaces, and fixing a bone plate across the injured joints.

84

A seven-month old male German Shepherd became acutely lame on the right forelimb 5 days ago. The dog presents on emergency due to acute exacerbation of lameness. On your exam, the dog has a temperature of 103.6 F (39.8 C) and was toe touching lame on the right forelimb and reluctant to stand or walk. There was no evidence of external trauma. Deep palpation of the right humerus elicited pain and you take radiographs of the right humerus which are shown below (see image). Based on the most likely diagnosis, what is the prognosis for this condition with supportive treatment only?

a. Excellent, >95% of dogs recover

b. Grave, <5% of dogs recover

c. Good, 80-90% of dogs recover

d. Poor, 10-20% of dogs recover

e. Fair, 40-60% of dogs recover

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a. Excellent, >95% of dogs recover

This is a case of panosteitis based on the young age of the patient and radiographic presence of focal intramedullary densities within the humeral diaphysis. Minor differentials could include osteomyelitis. Panosteitis is a self-limiting, painful condition characterized by limping and lameness. It typically affects the long bones of young dogs, usually between the ages of 5 to 18 months. It can occur with any breed, but it is more common in medium- to large-sized dog breeds.

Treatment is primarily supportive consisting of limiting activity and anti-inflammatory drugs. Pain lasts from weeks to months and resolves in nearly all cases. While these treatments reduce the pain associated with the condition, they may not alter the duration or course of the disease.

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85

A 2-year old male neutered German Shepherd presents with a history of intermittent lameness of the right pelvic limb. You do not appreciate any cranial drawer motion on exam and he has no pain in his long bones. On gait examination you notice a bunny-hopping type gait. What would you advise?

a. Radiographs of the right stifle due to a likely partial cranial cruciate rupture

b. Strict rest for 2 months and NSAID therapy for likely panosteitis

c. Testing for tick-borne disease

d. Pelviv radiographs to evaluate for evidence of dysplasia

d. Pelviv radiographs to evaluate for evidence of dysplasia

A bunny-hopping gait is most often seen in cases of hip dysplasia. Radiographs of the hips would be the next best step.

Since there is no cranial drawer movement, there is not likely a CCL rupture. Panosteitis can be seen in younger dogs which are growing and would cause pain in the long bones. Typically lameness from rickettsial disease is painful and may affect multiple joints or limbs.

86

A 5-month old male intact Doberman presents for forelimb lameness of 2 days duration. You localize the pain to the carpus on physical exam and take the following radiograph. What is your diagnosis?

a. Panosteitis

b. Hypertrophic osteodystrophy

c. Septic arthritis

d. Hypertrophic osteopathy

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b. Hypertrophic osteodystrophy

The radiograph shows the classic signs of hypertrophic osteodystrophy. There is a double physeal line in the metaphysis and areas of bony proliferation. The metaphyses are flared as well.

Panosteitis has a patchy trabecular pattern.

Hypertrophic osteopathy is a disease of older animals generally associated with metastatic disease. The main radiographic finding is periosteal reaction around the metacarpals, tarsals and digits. More than one limb is usually affected and if seen, further diagnostics to look for a primary site of neoplasia is warranted.

Soft tissue swelling and joint effusion are seen with septic arthritis and bony changes can be seen with chronic disease.

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87

Which of the following is not performed as part of the repair of medial patellar luxation in a dog?

a. Lateral imbrication

b. Partial meniscectomy

c. Transposition of the tibial tuberosity

d. Wedge resection

b. Partial meniscectomy

There is no reason to remove the menisci, as these are not involved with patellar luxation. A wedge resection involves making a deeper trochlear groove for the patella to slide in. Lateral imbrication and transposition of the tibial tuberosity will help pull the patella a little more laterally, as they are usually predisposed to luxating medially.

88

Which of the following is an appropriate objective in the repair of an articular fracture in a dog?

a. Avoid rigid fixation of the fracture

b. 50% or greater alignment

c. Early return to function

d. 6-8 weeks of strict post-operative rest

 

c. Early return to function

With articular fractures, the 3 major goals of the clinician are:

1) Rigid fixation of the fracture fragments; neglecting to do this will result in loose fracture fragments within the joints that will promote osteoarthritis.

2) Anatomic realignment (50% or even 75% is not adequate with articular fractures, in contrast to long bone fractures)

3) Early return to function. With long bone fractures, extended rest is recommended to promote stability and healing of the bone. The opposite is true in articular fractures where prolonged rest after repair will promote fibrosis, causing decreased range of motion in the joint.

89

A 6-year old male neutered Springer Spaniel presents for lethargy and difficulty walking. The owner reports that over the past week, the dog has become increasingly listless with decreased appetite and seems stiff as though he is "walking on eggs". You examine the dog and find joint pain and effusion bilaterally affecting the carpi, tarsi, stifle, and elbow. The dog also appears uncomfortable on firm spinal palpation. T-103.1 F (39.5 C), HR-118 bpm, RR-30 bpm with intermittent panting. The remainder of your physical exam is within normal limits. You perform a complete blood count and chemistry panel revealing the following:

Hematocrit - 32% (Normal 36%-50%)
White Blood Cell Count - 14,500/ul (Normal 7,000-17,000/ul)
Thrombocytes - 195,000/ul (Normal 200,000-900,000/ul)

Calcium - 10.8 mg/dl (Normal 8-11 mg/dl)
Phosphorus - 2.9 mg/dl (Normal 2.4-4.9 mg/dl)
Total Protein - 6.9 g/dl (Normal 5.5-7.3 g/dl)
Alkaline Phosphatase - 78 IU/l (Normal 10-80 IU/l)
Alanine Aminotransferase - 18 IU/l (Normal 3-33 IU/l)
Blood Urea Nitrogen - 17 mg/dl (Normal 10-22 mg/dl)
Creatinine - 1.1 mg/dl (Normal 0.5-2.2 mg/dl)
Glucose - 91 mg/dl (Normal 60-125 mg/dl)

Urinalysis was within normal limits and urine culture was negative. Radiographs of the affected joints show joint effusion and no bony abnormalities. You perform arthrocentesis of each carpus, the left elbow and right tarsus. You are able to aspirate up to about 0.3ml from each joint; the fluid is thin and turbid; you submit the fluid for analysis. The protein level in the joint fluid ranges from 3.2-3.5 g/dl and the nucleated cell counts are 12,000-18,000 cells/ul consisting primarily of neutrophils, approximately 90% of which are nondegenerate. Smaller numbers of mononuclear cells are present. Culture of the synovial fluid is negative and a panel for tick titers is all negative.

Which of the following treatments is most appropriate based on the presumptive diagnosis?

a. Arthroscopy and amoxicillin

b. Enalapril and furosemide

c. Prednisone and azathioprine

d. Doxycycline and enrofloxacin

e. Plasma transfusion and intravenous fluids

c. Prednisone and azathioprine

This case is most consistent with immune-mediated polyarthritis (IMPA). IMPA is often classified as being erosive or nonerosive. This case is an example of the nonerosive form based on the lack of radiographic evidence of cartilage or subchondral bone destruction. The erosive form is rare and is thought to account for <1% of the cases of IMPA.

Nonerosive IMPA can be associated with a variety of systemic diseases or precipitating factors including systemic infectious, inflammatory or neoplastic disease or reactions to drugs or vaccines but it is most commonly idiopathic with no association to another disease process. In the described case, no risk factors or signs of concurrent disease were mentioned. Tick-borne arthropathy is less likely with the negative tick titers obtained, but since not every type of tick can be tested for, some clinicians may opt to treat with an antibiotic like doxycycline concurrently with the immunosuppressive drugs.

The clinical signs associated with IMPA are anorexia, weight loss, fever, lethargy, and lymphadenopathy. Up to 25% of dogs present with only nonspecific signs of systemic illness and without apparent gait abnormality or joint effusion. It is an important consideration for dogs with fever of unknown origin and may be the cause up to 20% of the time. IMPA is diagnosed by synovial fluid analysis although additional baseline diagnostics are indicated to screen for potential systemic or infectious causes. Normal synovial fluid is clear and viscous with <2.5 g/dl protein and <3,000 cells/ul with predominantly mononuclear cells. Joint fluid in IMPA may be thin, turbid, and increased in volume with higher amounts of protein and cells, often primarily nondegenerate neutrophils.

Treatment of idiopathic IMPA centers on immunosuppressive therapy, often starting with prednisone and sometimes including an additional immunosuppressive drug such as azathioprine or cyclophosphamide. About 80% of dogs will respond to immunosuppressive doses of prednisone; however, about one half of dogs require long-term or additional drug therapy to maintain remissio

90

Which of the following reasons explains why Dalmatians are predisposed to urinary tract obstructions?
a. Dalmatians have a genetic defect in the immune system of their lower urinary tract, predisposing them to bacterial cystitis and the formation of struvite stones, which can cause urinary tract obstructions.

b. Dlmatians have a genetic defect in making allantoin from urates in their liver.  The low solubility of urates predisposes the dogs to forming urate stones, which can cause urinary tract obstructions.

c. Dalmatians are born with a congenital defect that predisposes them to urethral narrowing and the formation of urethral strictures.

d. Dalmatians have a genetic defect in the renal tubular reabsorption of cysteine, predisposing them to a build-up of cysteine and the formation of cysteine stones, which can cause urinary tract obstructions.

b. Dlmatians have a genetic defect in making allantoin from urates in their liver.  The low solubility of urates predisposes the dogs to forming urate stones, which can cause urinary tract obstructions.

The low solubility of urates predisposes the dogs to forming urate stones which can cause urinary tract obstructions. Medical management involves feeding a low purine diet to neutralize or alkalinize the urine pH and administration of allopurinol, a xanthine oxidase inhibitor.

91

What type of urinary stone is likely to form in an animal being treated with too much allopurinol?

a. Struvite

b. Urate

c. Calcium oxalate

d. Cysteine

e. Xanthine

e. Xanthine

Allopurinol is used in the treatment of urate stone forming Dalmatians. It acts by inhibiting the enzyme, xanthine oxidase, which metabolizes xanthine. The idea is that by stopping the purine metabolism pathway at this point, uric acid will not be formed in high quantities. However, if given at too high of a dose, xanthine will accumulate to levels where xanthine stones will form.

92

Which of the following is most suggestive of pyelonephritis?

a. Small, irregular kidneys on ultrasound

b. Bacterial or white blood cells in the urine

c. Pain on abdominal palpation

d. Bacterial or white blood cell casts in urine

d. Bacterial or white blood cell casts in urine

Bacterial or white blood cell casts are highly suggestive of a past or present bacterial infection in the kidneys. Bacteria or white blood cells in the urine may be due to cystitis. Small, irregular kidneys may be due to any chronic pathology in the kidneys. Pain on abdominal palpation can be caused by pain from any abdominal organ or structures adjacent to the abdomen. Other signs associated with pyelonephritis include fever, anorexia, depression, and vomiting. A nephropyelogram may show blunted, dilated calices and dilated, tortuous ureters. Renal biopsy and culture would give the definitive diagnosis of pyelonephritis.

93

You are presented with a 6-year old female spayed toy poodle mix who has a 4 day history of stranguria and pollakiuria. The owner says that this is the 3rd time she has had these signs in the last 4 months; each of the other times the signs resolved after a week of amoxicillin.

Physical exam is normal except for discomfort on bladder palpation.

CBC and chemistry panels are within normal limits. Urinalysis results are as follows:

USG = 1.030
pH = 8.5
Color = yellow
Clarity = turbid
Glucose = neg
Protein = 3+
Ketones = neg
RBC = 50-100/hpf
WBC = 20-30/hpf
Bacteria = ++++ cocci
Crystals = 4+ magnesium ammonium phosphate crystals

Abdominal radiographs show several large (>2 cm) rounded mineral opacities in the bladder.

What is the most likely diagnosis, and what are your treatment options?

a. Ammonium urate stones.  Treat with culture-based antibiotics, dietary dissolution, and management of underlying liver disease

b. Calcium oxalate stones.  Treat with culture-based antibiotics, and either dietary dissolution or surgical removal of stones.

c. Xanthine stones.  Treat with culture-based antibiotics, allopurinol, and increased dietary protein

d. Struvite urolithiasis.  Treat with culture-based antibiotics, and either dietary dissolution or surgical removal of stones

e. Cystine stones.  Treat with culture-based antibiotics, surgical removal and decreased dietary calcium

d. Struvite urolithiasis.  Treat with culture-based antibiotics, and either dietary dissolution or surgical removal of stones

Large bladder stones in the presence of UTI and alkaline urine are usually struvite, particularly when accompanied by struvite (magnesium ammonium phosphate) crystalluria. In dogs, struvite stones are almost invariably infection-associated. The infecting organisms are usually urease-producers (Staphylococus, Proteus, Klebsiella, some E. coli) which alkalinize the urine and favor struvite formation. The single most important long-term management is prevention of infection.

Calcium oxalate stones are usually small (1 cm or less), are often present in the absence of UTI, and cannot be dissolved.

Cystine stones occur most often in Newfoundland dogs, dachshunds, and bulldogs. They are radiolucent and occur due to metabolic defects.

Urate stones are usually small and many. They are frequently radiolucent and can be related to underlying liver disease.

94

A 6-month old Labrador Retriever presents for failure to thrive and stranguria. Abdominal ultrasound shows a small liver and stones in the urinary bladder. Abdominal radiographs show no visible stones. How can this be explained?

a. The dog has calcium oxalate stones

b. The dog has urate stones in its bladder

c. An artifact from the ultrasound was perceived as stones.  There are really no stones in the bladder

d. The dog has struvite stones

b. The dog has urate stones in its bladder

The dog is described as having a portosystemic shunt which is often accompanied by urate stones in the bladder. Urate stones (and cysteine stones) are radiolucent, so they can't be detected by radiography. Remember "I can't C U": ("C" is for cysteine, and "U" is for urate).

95

A 2-year old female spayed mixed breed dog presents in acute oliguric renal failure. The dog has a history of drinking ethylene glycol two days ago. What step should be taken next?

a. Start treating the dog with 4-Methylpyrazole IV and give a guarded to poor prognosis to the owner

b. Tell the owner the dog has a guarded to poor prognosis and may need hemodialysis

c. Start treating the dog with ethanol IV and give a guarded to poor prognosis to the owner

d. Start treating the dog with activated charcoal orally and tell the owner the dog has a guarded prognosis

 

b. Tell the owner the dog has a guarded to poor prognosis and may need hemodialysis

4-MP and ethanol act by preventing alcohol dehydrogenase from converting ethylene glycol to its toxic metabolites. In animals where oliguric renal failure has already begun, most of the ethylene glycol will already have been metabolized, so there is no benefit to giving ethanol or 4-MP. Activated charcoal should only be given if the ethylene glycol was ingested within 2 hours.

96

A 4-year old male castrated Basenji presents for polyuria, polydipsia, and weight loss. Blood work shows P=2.5 (2.9-5.3 mg/dl), K= 3.1 (3.9-5.1 mEq/L), total CO2= 12 (17-25 mmol/L). The remainder of the blood work is within normal limits. Urinalysis shows 3+ glucose. Which of the following is your most likely differential diagnosis?

a. Diabetes mellitus

b. Fanconi syndrome

c. Pyelonephritis

d. Pyometra

 

b. Fanconi syndrome

Fanconi syndrome is an inherited disease in Basenjis. The disease involves renal tubular defects causing an abnormal loss of electrolytes and solutes leading to hypophosphatemia, hypokalemia, and metabolic acidosis. DM is less likely because serum glucose is normal. The lab abnormalities present in this dog are not consistent with pyelonephritis. Pyometra is not a viable choice as the signalment describes a male.

97

What region of the bone is affected in hypertrophic osteodystrophy?

a. Physis

b. Epiphysis

c. Diaphysis

d. Metaphysis

d. Metaphysis

Hypertrophic osteodystrophy (HOD) is a condition seen in young, growing large breed dogs. It affects the metaphyses of all long bones and appears as an abnormal radiolucent line within the metaphysis. The disease is usually self-limiting but can cause limb deformities or systemic illness. The etiology is unknown but may be correlated with Ca/P levels and balance, vitamin C deficiency, and certain diseases including distemper.

98

In an animal with pleural effusion, which radiographic view will give you the best view of the heart?

a. Dorsoventral

b. Ventrodorsal

c. Left lateral

d. RIght lateral

b. Ventrodorsal

Pleural effusion obscures the heart completely on a dorsoventral radiograph and at least partially on lateral radiographs. Ventrodorsal positioning usually moves the pleural fluid away from the heart and allows for a radiographic view of the heart to be obtained. Of course, in dyspneic animals, it may not be wise to position them ventrodorsally.

99

A type III Salter Harris fracture involves what part of the bone?

a. Metaphysis and physis

b. Metaphysis, physis, and epiphysis

c. Epiphysis and physis

d. Metaphysis and epiphysis

c. Epiphysis and physis

A type I Salter-Harris fracture is physeal only. Type II involves the physis and metaphysis, type III involves the physis and epiphysis, type IV involves physis, metaphysis, and epiphysis, and type V is a compression injury to the physis.

100

A 12-year old English Bulldog presents with anorexia and severe, generalized pain. What is the best description of the lesions in this radiograph?

a. Monostotic, non-aggressive

b. Polyostotic, aggressive

c. Monostotic, aggressive

d. Polyostotic, non-aggressive

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b. Polyostotic, aggressive

There are multiple lytic lesions in the cervical and thoracic vertebrae, especially visible in C2 and in the spinous processes of the T1-T8. There are also lytic lesions in the proximal humerus of one leg and in the bones of the skull.

101

You are examining a dog for lameness and on radiographs; you find hypertrophic osteopathy of the metacarpal bones. What is the likely cause of this lesion?

a. Pulmonary neoplasia

b. Ca deficiency

c. Vitamin D deficiency

d. Bone tumor

e. Trauma

 

a. Pulmonary neoplasia

Hypertrophic osteopathy is visible as periosteal proliferation in the diaphyses of affected bones. Usually the metacarpal and metatarsal bones are affected first, and it may progress to the long bones. Lameness, pain, and swelling are usually evident. Joints are unaffected. The cause is usually primary or metastatic pulmonary neoplasia, although other diseases in the thorax including bronchopneumonia, Spirocerca infection, or congestive heart failure, may also be associated. Less commonly, abdominal neoplasia may be seen with this condition.

102

Which of the following is most likely to cause the abnormality seen in this radiograph?

a. Penetrating thoracic trauma

b. Osteosarcoma

c. Aspiration pneumonia

d. Pyometra

e. Blastomycosis

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b. Osteosarcoma

The abnormality in the radiograph is multiple pulmonary nodules consistent with metastatic neoplasia. Systemic fungal disease would be a reasonable differential for this radiographic pattern but is not as good of a choice, especially with no evidence of hilar lymphadenopathy. Aspiration pneumonia would cause an alveolar infiltrate centered in the cranioventral lung region, and penetrating trauma would likely cause pneumothorax. There is no evidence of pneumothorax in this study.

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103

A 6-month old Chocolate Labrador presents for limping and failure to gain weight. He is housed in an outdoor kennel with other hunting dogs. He is fed a large breed dry puppy food. He received his puppy shots at 8, 12, and 16 weeks old. He is quiet, alert, and responsive. His body condition score is 3/9, with rib exposure and poor fat deposition. His mucous membranes are pale pink, with a capillary refill time of 2 seconds. His heart and lungs auscult normally. No abnormalities are felt on abdominal palpation. He is an intact male, and both testicles are descended. The only abnormalities are the pads of his two front feet and left hind foot (see image) that he chews at frequently. What is diagnostic test of choice?

a. Radiographs

b. PCV and TP

c. Skin scraping

d. Fecal float

e. Biopsy

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d. Fecal float

Hookworms (Ancylostoma and Uncinaria) are intestinal parasites that suck blood and can cause anemia, enteritis, coughing during larval migration, and dermatitis. Any young dog that is failing to thrive and/or has pale mucous membranes should be tested for intestinal parasites. Hookworm dermatitis, also called Ancylostomiasis is typically seen in conditions with poor sanitation and/or in kennels.

Hookworms can be transmitted in utero, during nursing, or via 3rd stage larva penetrating the skin. The most commonly affected skin areas are the pads and interdigital spaces of the feet, but can include any surface that contacts the ground. The larva migrate through the dog's tissues before arriving in the intestines. They cause significant anemia, failure to thrive, or sudden death in young dogs. In mild cases, deworming protocols are often enough; with severe cases blood transfusions and parenteral treatments are often necessary.

Skin scraping and impression smears of the affected skin areas are typically unrewarding for isolating parasites. A PCV/TP would show signs of anemia, but not the underlying etiology. Complete blood cell count and chemistry will often show anemia that is regenerative and an eosinophilia. Radiographs would be unrewarding in this case. A biopsy may show migrating larva if biopsied soon after trauma, however this is not a diagnostic test routinely used.

104

Which of the following is the treatment of choice for a Taenia infection in dogs?

a. Fenbendazole

b. Pyrantel

c. Praziquntel

d. Ivermectin

 

c. Praziquntel

Pyrantel and ivermectin are not known to be effective against Taenia infections. Fenbendazole is effective against Taenia pisiformis, but not other subspecies of Taenia, making it a less desirable answer choice.

105

A 3-year old German Short Hair Pointer presents for vomiting, lethargy, and diarrhea. A fecal exam reveals the eggs of Nanophyetus salmincola, the salmon poisoning fluke. What treatment should be administered to treat the symptoms of the dog?
a. Penicillin

b. Fenbendazole

c. Tetracycline antibiotics

d. Praziquantel

c. Tetracycline antibiotics

The causative agent for the dog's clinical signs is Neorickettsia helminthoeca. Treatment of choice for this rickettsial agent is tetracycline antibiotics. The fluke itself is not responsible for the clinical signs, but may be treated effectively with Praziquantel.

106

Which of the following is most likely to be the vector for Lyme disease?

a. Dermacentor variabilis

b. Dermacentor andersoni

c. Ixodes pacificus

d. Rhipicephalus sanguineus

e. Amblyomma americanum

c. Ixodes pacificus

Ticks acquire the infection at any stage and are most likely to get it from the white-footed mouse, Peromyscus leucopus. Dermacentor variabilis and Dermacentor andersoni are known to transmit Rocky Mountain Spotted Fever. Amblyomma americanum may transmit canine granulocytic ehrlichiosis which is caused by E. ewingii and Anaplasma phagocytophila. Rhipicephalus sanguineus is known to transmit Ehrlichia canis.

107

A 12 year-old female spayed mixed breed dog presents for further evaluation of intermittent vomiting of 2 weeks duration. A general physical exam was performed and found to be unremarkable. Blood work was performed and the following abnormalities were observed: CK 1019 IU/L (52-368 IU/L), AST 106 U/L (13-15 IU/L), ALK Phos 864 U/L (1-114 IU/L), ALT 340 U/L (10-109 IU/L). An abdominal ultrasound was performed and revealed a massive, multilobular, heterogenous mass associated with the right medial liver lobe. The remaining liver lobes appeared to be unaffected. Based on the history, blood work, and findings what is the likely long-term survival of this patient if surgery is pursued and a hepatocellular carcinoma is diagnosed?

a. Approximately 28 days

b. Approximately 700 days

c. Approximately 1400 days

d. Approximately 300 days

 

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c. Approximately 1400 days

Single solitary liver masses are generally considered a surgical disease as long there is no overt evidence of metastasis or concern that the mass is a metastatic lesion as opposed to a primary tumor arising from the liver. Primary liver masses include hepatomas, hepatocellular carcinomas, bile duct adeonomas, bile duct carcinomas, and rarely, neuroendocrine tumors. Hepatocellular carcinomas are the most common liver tumor of dogs and second most common in cats. Adenomas will have a better prognosis, however hepatocellular carcinomas generally carry a good prognosis after surgical excision as well.

Bile duct carcinomas have a much more guarded prognosis with an average survival time of approximately 6 months. The prognosis for neuroendocrine tumors of the liver is poor.

108

What tumor type is most frequently implicated in causing feminization syndrome in dogs including gynecomastia, sexual attraction of males, and bilaterally symmetric alopecia?

a. Sertoli cell tumor

b. Mammary carcinoma

c. Seminoma

d. Leydig cell tumor

a. Sertoli cell tumor

The tumor sometimes secretes estrogen and other hormones, which can lead to this syndrome.

109

This radiograph is of a 10-year old male castrated mixed-breed dog that has been progressively more lame on the left forelimb over the past 3 weeks. Owners report that he has always been healthy and still has a great appetite. There is a travel history of visiting Nevada approximately 8 months ago. What is the recommendation for this patient?

a. Strongly recommend performing a total elbow replacement given the severe degree of osteoarthritic changes

b. Strongly recommend initiating glucosamine and chondroitin therapy as well as NSAIDs

c. Strongly recommend a CBC and chemistry panel and the initiate anti-fungal therapy for a minimum of six months

d. Strongly recommend chest radiographs and biopsy prior to initiating treatment

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d. Strongly recommend chest radiographs and biopsy prior to initiating treatment

This radiograph has a component of lytic and proliferative lesions that cross the joint. The differentials include neoplasia, fungal osteomyelitis, or bacterial osteomyelitis. Since the bony involvement is crossing the joint, it is most likely a synovial cell sarcoma. Osteosarcoma, fibrosarcoma, and chondrosarcomas are less likely to cross a joint as seen in this image. The marked lytic component seen should eliminate severe osteoarthritis as a differential. Anti-fungal therapy or any definitive treatment should ideally not be initiated until a diagnosis is obtained.

The radiograph shown here was actually taken after obtaining a core biopsy of the bone for histopathology.

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110

A 10-year old Shih Tzu presents for collapse. A diagnostic work up shows a mass on the right kidney, which was subsequently removed and biopsied as renal carcinoma. Which one of the following can be associated with renal carcinoma?

a. Polycythemia

b. Hyperadrenocorticism

c. Hyperestrogenism

d. Thrombocytopathy

e. Hypercalcemia

a. Polycythemia

Renal carcinomas have been associated with erythropoietin secretion, causing elevations in hematocrit as a paraneoplastic syndrome.

Hypercalcemia is associated with anal sac adenocarcinomas, lymphomas and other tumors.

Thrombocytopathy can be seen with hemangiosarcoma and multiple myeloma.

Hyperestrogenism can be seen with Sertoli cell tumors.

Hyperadrenocorticism is caused by functional adrenal or pituitary tumors.

111

A 12-year old mixed breed MC dog presents to an emergency clinic with a history of increased respiratory rate, anorexia, lethargy, inappetance and a soft cough over the past 3 days. One week ago the patient had a large mass removed from the left pelvic limb. The owners are unable to tell you the diagnosis of the mass. On physical exam, the patient is depressed, has slightly decreased lung sounds, and the incision associated with mass removal is intact. Chest radiographs were performed as shown in this image. What is the radiographic diagnosis and appropriate treatment?

a. The patient has severe bronchoconstriction and a bronchodilator should be prescribed

b. This patient has metastatic lesions throughout the lungs and only palliative treatment can be recommended

c. The patient has severe aspiration penumonia and should be started on broad spectrum antibiotics, IV fluids, and oxygen support

d. The patient has severe pulmonary edema secondary to heart failure and durosemide should be administered.

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b. This patient has metastatic lesions throughout the lungs and only palliative treatment can be recommended

This dog was not staged prior to surgical removal of the mass and likely had visible metastatic nodules at the time of surgery. The only other potential differential with this radiographic finding would be granulomatous disease which is unlikely given the history.

 

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112

A 7-year old female Lhasa Apso presents to you for lethargy and inappetence. On your exam, you detect mandibular lymphadenopathy and perform a fine needle aspirate. You see the aspirate depicted here. Which of these treatments would be given to this patient as part of a first line therapy?

a. Carboplatin

b. Itraconazole

c. Doxycycline

d. Prednisone

e. Milbemycin

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d. Prednisone

This is a case of lymphoma. The cytology depicts the classic finding of a population of lymphoid cells that are predominantly lymphoblasts based on their size and characteristics. If you were unsure about their size due to magnification, there is a neutrophil in the lower left corner for comparison. The lymphoblasts are considerably larger than the neutrophil. Mature lymphocytes would be smaller than a neutrophil. Note that there is a mitotic figure in the middle of the slide.

There are many treatments and protocols for lymphoma and some of the main agents known to have efficacy are prednisone, doxorubicin, cyclophosphamide, vincristine, L-asparaginase, and lomustine. There are many other efficacious chemotherapeutics for lymphoma but carboplatin is not considered a first line treatment for lymphoma in dogs.

The other drugs listed are antifungal (itraconazole), antibiotic (doxycycline) and anti-parasitic (milbemycin).

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113

What type of tumor in the dog is commonly associated with signs of local inflammation as shown in the image?

a. Cutaneous melanoma

b. Mast cell tumor

c. Hemangiosarcoma

d. Mammary carcinoma

e. Lymphoma

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b. Mast cell tumor

Mast cells contain granules with inflammatory mediators including heparin and histamine and commonly cause local inflammation. They can also cause paraneoplastic signs associated with hyperhistaminemia and hyperheparinemia.

Half of mammary tumors in dogs are benign and half are malignant. Even the malignant ones do not usually have associated inflammation with the noteworthy exception of a relatively rare type of tumor called an inflammatory mammary carcinoma that carries a very poor prognosis.

Hemangiosarcoma and lymphoma are both malignant tumors but are not usually associated with extensive inflammation. Cutaneous melanoma in the dog is benign in 80-90% of cases in contrast to humans.

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114

Which of the following is a common finding on a complete blood count in a dog with a ruptured splenic hemangiosarcoma?
a. Thrombocytosis

b. Eosinophilia

c. Neutropenia

d. Schistocytes

e. Heinz body anemia

d. Schistocytes

Schistocytes are fragmented red blood cells that are mechanically broken up due to the irregular vessels and fibrin strands they pass through in hemangiosarcoma patients. Other typical findings on a CBC in a patient with hemangiosarcoma are thrombocytopenia, anemia (although not with Heinz bodies), and leukocytosis.

115

A 10-year old female spayed boxer presented for a mass on the left side of the neck. The mass was diagnosed as a mast cell tumor based on fine needle aspirate. Screening with thoracic radiographs, abdominal ultrasound and bloodwork was unremarkable. The owners elected for surgical removal and clean 3 cm margins were obtained in all directions. The mass was submitted for histopathology and was categorized as a grade 3 (or high grade) tumor. What is your recommendation to the owner?

a. Start a tyrosine kinase inhibitor chemotherapy drug

b. Monitor the surgical site for recurrence; abdominal ultrasounds every 3-4 months

c. Radiation therapy for the surgical site and prescapular lymph node; abdominal ultrasound every 3-4 months

d. Start a doxorubicin based chemotherapy protocol

a. Start a tyrosine kinase inhibitor chemotherapy drug

Under the Patnaik grading system, grade 3 tumors are highly metastatic. Mast cell tumors are highly responsive to radiation therapy, but with clean excision and wide surgical margins, local recurrence is unlikely. Metastasis is the primary concern and a wait and monitor approach is not advised. Even with no evidence of metastasis at the time of surgery, chemotherapy should be initiated as soon as possible. Common protocols include single agent or alternating vinblastine and lomustine. Tyrosine kinase inhibitors, such as toceranib (Palladia) and masitinib (Kinavet, which is no longer available), target c-kit, a stem cell factor receptor involved in mast cell proliferation and differentiation. Palladia and Kinavet are FDA approved for treatment of high-grade canine cutaneous mast cell tumors.

116

A 6-year old Schipperke presents with a 1-month history of progressive weakness and decreased appetite. The owner reports the dog is slightly polyuric and polydipsic. Your physical exam is unremarkable except that the dog seems subdued and a bit uncomfortable. You perform bloodwork which shows the following results:

Hematocrit - 28% (Normal 36%-50%)
White Blood Cell Count - 16,000/ul (Normal 7,000-17,000/ul)
Thrombocytes - 324,000/ul (Normal 200,000-900,000/ul)
Calcium - 13.2 mg/dl (Normal 8-11 mg/dl)
Phosphorus - 2.9 mg/dl (Normal 2.4-4.9 mg/dl)
Total Bilirubin - 0.1 mg/dl (Normal 0.06-0.61 mg/dl)
Total Protein - 7.2 g/dl (Normal 5.5-7.3 g/dl)
Albumin - 2.3 g/dl (Normal 2.2-4.2 g/dl)
Globulins - 4.9 g/dl (Normal 2.6-4.5 g/dl)
Alkaline Phosphatase - 45 IU/l (Normal 10-80 IU/l)
Aspartate Aminotransferase - 8 IU/l (Normal 0-20 IU/l)
Alanine Aminotransferase - 17 IU/l (Normal 3-33 IU/l)
Gamma-Glutamyl Transferase - 2 IU/l (Normal 1.3-12 IU/l)
Blood Urea Nitrogen - 17 mg/dl (Normal 10-22 mg/dl)
Creatinine - 1.4 mg/dl (Normal 0.5-2.2 mg/dl)
Glucose - 96 mg/dl (Normal 60-125 mg/dl)
Cholesterol - 180 mg/dl (Normal 125-250 mg/dl)

You perform whole-body radiographs which are shown below. Which of the following choices are two tests that will help you confirm the most likely diagnosis?

a. Urinalysis, renal biopsy

b. Bone marrow biopsy, serum electrophoresis

c. Ultrasound of neck, measure serum parathyroid hormone

d. ACTH stimulation test, dexamethasone supression test

e. Echocardiogram, heartworm antigen test

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b. Bone marrow biopsy, serum electrophoresis

This dog has signs and bloodwork findings that are consistent with but not specific for multiple myeloma. The hypercalcemia and hyperglobulinemia are both mild and are consistent with this diagnosis but would not be sufficient alone to jump to that conclusion. The key finding in these case is the radiographic evidence of multiple punctate lucencies including in the body of C4, several of the thoracic dorsal spinous processes, the left ilium, and the right and left humeral diaphyses. These lesions are strongly suggestive of multiple myeloma; however, definitive diagnosis of multiple myeloma requires satisfying at least two of the following criteria:

1. Monoclonal gammopathy
2. Radiographic evidence of osteolytic bone lesions (satisfied in this case)
3. >5% neoplastic cells or >10-20% plasma cells in the bone marrow
4. Immunoglobulin light chain proteinuria (Bence-Jones proteinuria)

Therefore, the best answer in this question is to perform serum electrophoresis to assess monoclonal gammopathy and a bone marrow biopsy to look for neoplastic infiltration of plasma cells.

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117

Which of these is a major potential adverse side effect of the chemotherapeutic drug adriamycin in dogs?

a. Cardiotoxicity

b. Ileus

c. Nephrotoxicity

d. Anaphylaxis

e. Cystitis

a. Cardiotoxicity

In addition to the usual side effects of chemotherapeutic drugs such as myelosuppression and GI side effects, a major concern with adriamycin administration is dose dependent cardiotoxicity. The drug that causes ileus is vincristine. The drug that causes anaphylaxis is L-asparaginase. The drug that causes nephrotoxicity is cisplatin. The drug that causes cystitis is cyclophosphamide.

118

Which of the following problems is seen more frequently in male dogs than females?

a. Urinary tract infections

b. Addison's disease (hypoadrenocorticism)

c. Mammary cancer

d. Aggression

e. Adenocarcinoma of the anal sac

d. Aggression

More males than females present to veterinary behaviorists for aggression. The other diseases listed have been reported or suggested to occur more frequently in females in some reports.

119

A 3-month-old pit bull terrier presents with generalized alopecia and crusting of the skin (see image). A deep skin scraping shows the dog has generalized demodicosis. What should you tell the owners?

a. Transmission of the infection was from the bitch to the puppy.  The bitch be treated for Demodex because she is the source of the infection.  The puppy does not need to be treated.

b. The dog likely has an inherited defect in cellular immunity.  The dog should not be bred

c. It is very common for pit bull puppies to get generalized Demodex infections.  The puppy should be treated for the infection, but the prognosis is good

d. Generalized Demodex infections usually resolve on their own without treatment

 

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b. The dog likely has an inherited defect in cellular immunity.  The dog should no

The dog should not be bred. Generalized demodicosis in juveniles and puppies is usually caused by an inherited defect in cell immunity. They should be treated with a mite killing agent like ivermectin, amitraz, or milbemycin, as well as with oral antibiotics for secondary bacterial infections. Spontaneous remission of the infection can occur, but the prognosis is always guarded. Demodex mites are part of the natural flora of a dog's skin, so they are normally present all the time. Adult dogs that develop generalized demodicosis are usually immune-suppressed.

120

Which dog breed is genetically predisposed to exocrine pancreatic insufficiency?

a. German Shepherd Dog

b. Bernese Mountain Dog

c. Irish Setter

d. Golden Retriever

 

a. German Shepherd Dog

EPI is believed to be an autosomal recessive trait in German Shepherd Dogs that results in atrophy of the exocrine pancreas. Dogs lose the ability to digest fat and protein and become emaciated. They have voluminous, soft feces, a voracious appetite, and may develop pica. The trypsin-like immunoreactivity (TLI) is diagnostic for EPI. Treatment entails adding powdered pancreatic enzyme extract, or raw pancreas to meals. These dogs should not be bred.

121

Which of the following breeds is predisposed to acanthosis nigricans?

a. Dachshund

b. Boxer

c. Chihuahua

d. Great Dane

e. Labrador Retriever

a. Dachshund

The primary inherited form of this condition almost exclusively occurs in Dachshunds. Other dogs may get a form of the condition secondary to other skin diseases. The condition is characterized by hyperpigmentation of the axillary and groin regions and can spread to other parts of the body. Secondary bacterial infections, yeast infections, and seborrhea commonly develop in the affected regions. The mode of inheritance has been proposed to be autosomal recessive or polygenic inheritance.

122

You are evaluating the blood work of a dog that is hit by a car. These are the following findings:
HCO3-12 mmol/L (17-24 mmol/L)
Total CO2-14 mmol/L (14-26 mmol/L)
Lactate-2.3 mmol/L (0.5-2.0mmol/L).

What is your assessment?

a. Metabolic alkalosis

b. Respiratory acidosis

c. Metabolic acidosis

d. Respiratory alkalosis

c. Metabolic acidosis

A low bicarbonate and total CO2 level is consistent with a metabolic acidosis. An elevated blood lactate of greater than 2.0 mmol/L implies that there is anaerobic metabolism occurring in this patient as a result of inadequate tissue perfusion, perhaps due to bleeding and trauma.

Nothing can be said about respiratory acidosis or alkalosis because no PaCO2 or pH is provided.

123

A 10 year old female spayed Schipperke dog presents to your emergency clinic for profuse vomiting for several days and weakness. You perform initial bloodwork and find that her blood pH is 7.6 (7.35-7.45) and her potassium is 1.8 mmol/L (3.4-4.9 mmol/L). She weighs 12 kg. You immediately start her on intravenous fluids supplemented with potassium. What is the maximum rate of intravenous potassium that would be considered safe to administer to this dog?

a. 12 mEq/hr

b. 24 mEq/hr

c. 18 mEq/hr

d. 3 mEq/hr

e. 6 mEq/hr

e. 6 mEq/hr

The maximum safe rate of potassium infusion is 0.5 mEq/kg/hr. As this dog weighs 12 kg, the maximum is 6 mEq/hr. This is one of those rates that you need to know. Administering potassium more rapidly than this can result in fatal arrhythmias.

124

A 4-year old female spayed mixed breed dog presents for further evaluation. She has a 24 hour history of increased respiratory rate and decreased appetite. Owners note that she is an indoor/outdoor dog. Based on these radiographs, what is the best treatment?

a. Left caudal lung mass removal

b. Pericardiocentesis

c. Intravenous furosemide

d. Thoracocentesis

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d. Thoracocentesis

This patient has a left sided pneumothorax. Pneumothorax can be secondary to trauma, ruptured bullae, infection, or neoplasia. The radiograph shows an elevated heart off the sternum as well as collapse of the lung lobes. Notice there are no bronchi or vessels extending caudally toward the diaphragm due to collapse of the lung.

Pericardiocentesis would be indicated if you had a very large globoid heart, suggestive of pericardial effusion. The heart does not appear enlarged and there is no pulmonary edema making intravenous furosemide a poor choice. Do not confuse a collapsed lung lobe for a lung mass.

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125

In a dog, Cushing's response is characterized by a _______.

a. Compensatory decrease in systolic blood pressure to maintain peripheral perfusion

b. Conpensatory hyperadrenocorticism to maintain cerebral perfusion

c. Compensatory increase in mean arterial pressure to maintain cerebral perfusion pressure

d. Compensatory elevation in blood glucose to enhance cerebral function

c. Compensatory increase in mean arterial pressure to maintain cerebral perfusion pressure

Cerebral perfusion pressure= Mean arterial pressure - intracranial pressure or (CPP=MAP-ICP).

This response is seen in situations where intracranial pressure increases such as in brain trauma. In this case, you need to think before you intervene to decrease your patient's mean arterial pressure as this might eliminate cerebral blood flow and kill your patient.

126

A 9 year old Greyhound presents to your clinic with an ulcerating mast cell tumor, located subcutaneously over the left scapula. You immediately schedule the dog for a wide surgical excision after no evidence of metastatic disease is identified on a complete blood count, serum chemistry, thoracic radiographs, and abdominal ultrasound. Your technician asks you if there are any drugs she should avoid using in this dog. You tell her the following drugs are contraindicated in this patient:

a. Acepromazine and ivermectin

b. Atracurium and acepromazine

c. Ivermectin and thiopental

d. Propofol and morphine

e. Morphine and thiopental

e. Morphine and thiopental

In this case, thiopental is contraindicated because the patient is a sighthound. Thiopental is an ultra-short acting barbiturate. Recovery depends on redistribution to tissues, including fat. Because sighthounds have very little fat, they have prolonged recoveries and greater complications with these drugs.

Morphine is contraindicated in this patient due to the ulcerating mast cell tumor. Morphine can cause histamine release and should be avoided in mast cell tumor patients.

127

A 2-year-old neutered male greyhound presents for crusting along his ear pinnae and elbows. The owner also explains that the dog is intensely pruritic. The dog mainly lives indoors but is also let outside into the backyard. The owner lives on a large rural property that is heavily wooded. You perform cytology, which returns negative for bacteria and yeast. You are highly suspicious of Sarcoptes. Which of the following would be most useful to help in your diagnosis of Sarcoptic mange?

a. Pinnal-pedal reflex, clinical signs, superficial skin scrape

b. Deep skin scrape, pinnal-pedal reflex, clinicla signs

c. Clinical signs, superficial skin scrape, trichogram

d. Histopathology, deep skin scrape, trichogram

e. Superficial skin scrape, histopathology, trichogram

Pinnal-pedal reflex, clinical signs, superficial skin scrape

A superficial skin scrape is most useful. A deep skin scrape is used for Demodex mites, which reside in the hair follicles. Superficial skin scraping is indicated for Sarcoptic mange, since this mite lives in the stratum corneum. Pinnal-pedal reflex can be positive in 70% of Sarcoptic mange infestation but can also be positive in any dog with pruritus. Clinical signs are helpful because Sarcoptes typically infects the non-haired portions of the skin such as the ear pinnae, elbows, hocks, and ventral abdomen. If the mite is not found on skin scraping and you have clinical signs indicative of Sarcoptes then a therapeutic trial is warranted. Keep in mind that in most cases you will not be able to find the mite.

A trichogram would not be indicated. This method can be used to diagnose dermatophytosis and sometimes Demodex. Histopathology will reveal a perivascular dermatitis that is non-specific. Rarely are the mites found on histopathology.

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128


A 2-year old female spayed Dachshund presents for further evaluation as a result of a mass on the pinna noted by the owner. On physical exam, the only abnormality noted was this mass. Cytology is consistent with a histiocytoma. Which of the following is the most reasonable treatment option?

a. Chemotherapy using lomustine

b. Radiation therapy

c. Benign Neglect

d. Cryotherapy

e. Radical surgical excision

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c. Benign Neglect

Histiocytomas are typically benign and will often present as a small, raised mass that may or may not be ulcerated. Fortunately, these masses usually regress on their own, and surgical or medical intervention is typically not necessary.

129

A 5-year old Collie presents for erosive/ulcerative dermatitis of the nasal planum. The lesion is well-demarcated and confined to the nasal planum and philtrum. There is a loss of cobblestone appearance and hypopigmentation. Which of the following is least likely to result in the above clinical signs?

a. Pemphigus foliaceous

b. Discoid lupus erythmatosus (cutaneous lupus)

c. Dermatophytosis

d. Mucocutaneous pyoderma

e. Cutaneous lymphoma

c. Dermatophytosis

Pemphigus and discoid lupus are autoimmune conditions that can result in ulcerative nasal dermatitis with loss of cobblestone appearance. Cutaneous lymphoma, in rare cases, can affect just the nose. Mucocutaneous pyoderma can also result in similar signs, but this condition usually has involvement in other areas such as the mucocutaneous junctions of the mouth, prepuce, and anus.

Dermatophytosis (ringworm) often affects the muzzle; however, it rarely affects the nasal planum. This is because dermatophytes live in hair follicles and there are no hair follicles on the nasal planum. Many times you will observe dermatophytosis on the muzzle and the lesions will stop abruptly where the nasal planum starts.

The next step for this dog would be to biopsy.

130

A 4 year-old neutered male Doberman Pinscher presents for symmetrical alopecia, lethargy, and weight gain despite a normal appetite. The owner reports that the dog has recently become very itchy. Upon dermatological examination, you find areas of alopecia on the flanks and axillary region. There is also erythema and waxy crusts involving the axillae and forelegs. You take cytology from these areas and find Malassezia. Complete blood count reveals a mild normochromic, normocytic anemia. Chemistry panel shows a very mild hypercholesterolemia. What is your next treatment and next diagnostic step?

a. Griseofulvin, free T4

b. Fluconazole, intradermal allergy test

c. Griseofulvin, intradermal allergy test

d. Doxycycline, free T4

e. Fluconazole, free T4

e. Fluconazole, free T4

From the options listed, fluconazole is the best treatment plan for this dog's Malassezia dermatitis. Griseofulvin is an antifungal but is expensive and causes myelosuppression and gastrointestinal upset; it is not the first choice for Malassezia dermatitis. Other azoles like itraconazole and ketoconazole are also good choices. Terbinafine is being used more often for Malassezia dermatitis since it has fewer side effects than azoles. Ketoconazole, itraconazole, and fluconazole can be hepatotoxic.

Underlying causes of Malassezia dermatitis include allergies, endocrinopathy, immunodeficiency syndromes, and other systemic illnesses. This dog is presenting with classic signs of an endocrinopathy with initially non-pruritic symmetrical alopecia. The clinical signs of lethargy and weight gain along with the blood work results is indicative of hypothyroidism, and your next diagnostic step would be a free T4. Intradermal testing is not recommended at this time, since the dog was initially not itchy and only became pruritic presumably after infection with Malassezia.

Doxycycline would not be indicated since it is an antibiotic.

131

A 4-month old intact male Collie presents for severe dermatitis along his nose and ears (see image). The areas are sensitive on palpation but not pruritic. No other areas are affected. Skin scraping and cytology are negative for mites or bacteria. Fungal culture is negative. Anti-nuclear antibody tests are ordered and are also negative. How do you educate the owner based on your presumptive diagnosis?

a. Long-term immunosuppressive medications are needed

b. Biopsy and culture are necessary, long-term therapy often needed

c. The disease is not curable; euthanasia should be discussed

d. The disease is familial, and is often cyclic and will regress

 

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d. The disease is familial, and is often cyclic and will regress

Familial dermatomyositis is a familial disease seen in Collies, Shetland sheepdogs, and other collie breeds. Diagnosis can be made with skin or muscle biopsies, but can be difficult as the clinical and histopathologic signs can wax and wane. Inciting causes can include vaccinations, sunlight, viral infections, or drugs. Some cases; however, will come and go without obvious inciting causes. Some cases can become severe enough to include muscle atrophy; megaesophagus has also been seen with this disease.

Treatments are often symptomatic and supportive and include Vitamin E supplements, Omega 3 fish oils, treatments for any secondary bacterial infections, and pentoxifylline. Prednisone can also be used to get more severe cases under control. Avoiding prolonged sun exposure can also help.

Educating the owner on the fact that signs will reoccur despite treatment can alleviate some owner frustrations. Often times signs will regress with or without treatments. Educate owners on neutering animals to prevent propagation of diseased animals.

132

A 1-year old male Shar Pei presents with the clinical signs shown in the photo below. Recognizing that this sign is classic for Familial Shar Pei Fever (FSF), what other finding is LEAST likely to be present?

a. Normal synovial fluid cytology

b. Panosteitis

c. Body temperature between 105 and 107 degree F

d. Proteinuria

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b. Panosteitis

Familial Shar Pei Fever (FSF) is characterized by high fever and unilateral or bilateral tarsal swelling as seen in the photo. This swelling affects tissues around the joint, rather than within the tarsus itself. FSF may be a distinct entity from amyoloidosis but animals with FSF are predisposed to amyoloidosis, resulting in proteinuria. Panosteitis is not associated with FSF.

133

A 9-year old female spayed Chihuahua presents to you with the skin abnormality shown below. She has similar lesions all over the rest of her body. A superficial and deep skin scraping show many moving "cigar shaped" mites. Which of these products is the only FDA approved for treatment of this disease?

a. Lime Sulfur

b. Ivermectin (Ivomec)

c. Amitraz (Mitaban)

d. Chlorhexadine

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c. Amitraz (Mitaban)

This is a case of generalized demodicosis which can occur in older dogs as well as young dogs. It is caused by the commensal mite, Demodex canis, and is often secondary to an underlying disease or immunosuppression. There are several treatment options (and you should probably know them all) but the only FDA-approved treatment is Amitraz (Mitaban). Ivermectin and milbemycin are also used to treat this condition in part because it is difficult to obtain Mitaban. Mitaban is used as dip and should be administered in a hospital, which is time consuming when there are other treatment options that can be similarly effective although used "off-label". Mitaban should be used cautiously in animals with skin lesions since more systemic absorption of Mitaban will occur which increases the likelihood of toxic affects.

134

A 14-year old Husky presents for the signs seen here (see image). What do you tell the owner regarding prognosis?

a. Permanent discoloration will spread over entire body

b. Color change may occur seasonally

c. May ulcerate, immunotherapies needed

d. This will reverse after treatment

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b. Color change may occur seasonally

This is seasonal nasal hypopigmentation. Season associated lightening of the nasal planum occurs during winter months and can darken in the spring and summer. Complete depigmentation is not noted. Hypopigmentation and discoloration of the nose and mucocutaneous junctions can vary from benign immune-mediated diseases, such as vitiligo that lower the amount of melanocytes in the skin to seasonal variations in coloring, commonly called a "Dudley Nose" or "Snow Nose". Certain breeds are more predisposed than others, such as Siberian Huskies, Golden and Labrador Retrievers, and Bernese Mountain Dogs. This can be seen in any breed.

With vitiligo, which is a benign immune related depigmentation, antimelanocyte antibodies can be found in circulation and a biopsy will show decreased melanocytes. Typically multiple areas will be affected, including ear tips, footpads, claws, and hair coat. Breeds predisposed to vitiligo can include German Shepherd Dogs, Collies, Rottweilers, Doberman Pinschers, and Giant Schnauzers

There are no treatments to prevent these disorders, and they typically cause no harm to the animals.

135

The patient imaged below is a 5 year-old male castrated dog that has been afflicted with pemphigus vulgaris. The patient's lesions are located at the mucocutaneous junctions including the prepuce, anus, and gingiva. Given the likely treatment regimen of this patient, which of the following medications would you not prescribe?

a. Fluconazole

b. Maropitant

c. Enrofloxacin

d. Firocoxib

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d. Firocoxib

Pemphigous vulgaris is an auto-immune disease which requires immunosuppressive therapy. This patient is likely on a steroid and possibily other immunosuppressives. Firocoxib (Previcox) is a nonsteroidal anti-inflammatory (NSAID) with specific inhibition at the Cox-2 sites and sparing of Cox-1 receptors. As with any NSAID, it is contraindicated to give this medication in conjuction with a steroid due to the high likelihood of side effects. Combination of an NSAID with a steroid may result in renal compromise and failure, in addition to gastric ulceration and increased risk of gastrointestinal perforation.

The other medications listed have no known adverse side effect when given with a steroid. Enrofloxacin has been known to cause blindness in cats at high doses. Maropitant is a popular anti-emetic/anti-nausea medication used in small animals. This medication has the potential of accumulating, therefore a washout period is recommended if used for more than 5 days. Fluconazole is a fungistatic triazode. It has the potential for hepatoxicity and therefore patients on this medication should have their liver parameters periodically evaluated.

136

A 4-year old male neutered mixed breed dog presents for a one-month history of weight loss, coughing, and limping. The owner recently noticed swelling and draining wounds on his legs (see image). The dog is on flea and tick preventative and heartworm preventative. The dog recently moved with the owner from Mississippi. The dog has a temperature of 103F (39.4 C). His lungs sound harsh and no murmurs are ausculted. Multiple nodules are felt under the skin along his legs; a few of which are draining a yellow to clear material that is not malodorous. His blood work shows a monocytosis, neutrophilia, low albumin, and elevated globulins. What is contraindicated?

a. Animal-human interaction

b. Biopsy

c. Radiographs

d. Cytology of discharge

e. Glucocorticoids

 

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e. Glucocorticoids

Based on physical exam findings, bloodwork, and history, fungal infection should be the primary differential. This is blastomycosis, a fungus whose spores are found predominantly throughout Ohio, Mississippi, and Tennessee. Spores are typically inhaled causing pulmonary disease before disseminating throughout the body. Commonly affected organs include the skin, bones, eyes, lymphatic system, and lungs. Less commonly affected organs can include the prostate, mammary glands, heart, and CNS.

Diagnosis can often be made on cytology of draining wounds. Biopsy of affected areas can also demonstrate organisms. AGID and antigen testing can detect Blastomycosis as well; however, you may have false negative AGIDs with early infection and the urine antigen test can be cross-reactive with Histoplasmosis.

Treatment can be difficult and includes antifungals, often long term, and NSAIDs. Glucocorticoids are often contraindicated as they may cause further immunosuppression. Some studies have shown that brief use of intravenous dexamethasone in the face of life threatening dyspnea during treatment with anti-fungals may be beneficial, but this is currently still under scrutiny.

Zoonotic transmission is generally low in living animals. Few reports of infection through dog bites have been reported. Necropsies of infected animals have resulted in infections through needle sticks, cuts, or inhalation. Warn owners the disease is an environmental pathogen, and can cause infection in people living in endemic areas.

Radiographs may show osteomyelitis of bones and nodular to diffuse interstitial patterns in the lungs. Pulmonary signs can mimic metastatic lesions. Severity can indicate overall prognosis.

137

Which of the following endocrine imbalances does not commonly cause a dermatosis in dogs?

a. Central diabetes insipidus

b. Hyperadrenocorticism

c. Sertoli cell tumors

d. Hypothyroidism

 

a. Central diabetes insipidus

Males with Sertoli cell tumors may develop bilateral alopecia with occasional pruritus and papular eruptions. Hypothyroid dogs often develop alopecia, seborrhea, and pyoderma. Hyperadrenocorticism patients commonly develop hyperpigmentation, alopecia, calcinosis cutis, seborrhea, and pyoderma.

138

A 7-year old German Shepherd dog presents for a second opinion of bilateral distal forelimb wounds. The owners note that they are not excessively pruritic but the patient will lick at the region. A biopsy had previously been performed with a microscopic description of chronic focal nodular pyogranulomatous dermatitis and destructive furunculosis without evidence of neoplasia or underlying etiology. In light of these findings, acral lick dermatitis is suspected. Which of the following is NOT a reasonable treatment strategy?

a. Combined systemic triamcinalone and clindamycin therapy

b. Basket muzzole or E-collar

c. Ivermectin and prednisone therapy

d. Fluoxetine

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c. Ivermectin and prednisone therapy

Acral lick dermatitis is considered a chronic and repetitive condition in which a dog continuously traumatizes a region as a result of obsessive licking. The licking is usually secondary to pruritis from allergies and will lead to infection. There could be multiple causes for this such as a neuropathy or underlying orthopedic disease; however, this behavior is considered to be obsessive-compulsive, and the patient may need to be evaluated for other anxiety related behaviors.

Since these lesions are not parasitic in origin the answer choice with Ivermectin is considered the poorest treatment option. All other choices may be used alone or in combination to help break the cycle and achieve healing of the lesion. Triamcinalone is a steroid. Clindamycin is an antibiotic. Fluoxetine (aka Prozac) is used to treat depression and obsessive-compulsive disorders. Basket muzzles and e-collars are commonly used as well to help stop the licking.

139

A 3-year old German Shepherd presents for multiple subcutaneous nodules on the right front limb that have been present for about one week. The dog is otherwise healthy. The owner states that the dog lives mostly outdoors in a wooded area with ponds in Florida. You are highly suspicious of pythium; what is the best therapeutic option for this disease?

a. Prednisone

b. Ivermectin

c. Lufenuron

d. Antifungal therapy

e. Amputation and treatment with an antifungal

f. Amputation and treatment with doxycycline

e. Amputation and treatment with an antifungal

Pythium is an aquatic organism that inhabits ponds of the Southeast United States. These organisms have different cell walls than regular fungi, which makes them difficult to treat since most antifungal treatments target fungal cell wall synthesis. Prognosis is extremely poor with this disease and amputation (if the lesions are localized to an affected limb) is currently the best option. Amputation should always be followed with multiple long-term antifungal therapies. Owners should be warned that local postoperative recurrence is common. Dogs are most commonly affected, but this disease can also occur in cats. It has also been reported in humans and horses.

Doxycyline is an antibiotic and would not be effective for this disease. Prednisone would be contraindicated for pythium. Lufenuron is a chitin synthesis inhibitor used for flea control and would not be effective. Ivermectin is an anti-parasite drug and would not be effective.

140

A 7-year-old mixed breed dog presents for re-evaluation of demodicosis and severe flea allergic dermatitis. The dog's skin is doing much better since being on Ivermectin, and you plan to continue treatment. The owner is very concerned about the area around the tail base, as the patient has been extremely pruritic in that region. You suspect flea allergy dermatitis and ask the owner if she is still using flea medications. The owner explains that she stopped the flea medication when Ivermectin was started. You ask about the other animals in the household, and the owner replies that the rabbit and cat have no clinical signs. The owner also states that the cat and rabbit continue to sleep with the dog despite his skin condition. Which flea medication would be a good choice for this patient?

a. Permethrin

b. Afoxalaner

c. Pyriproxyfen

d. Lufenuron

e. Spinosad

b. Afoxalaner

From the list of medications Afoxalaner (Nexguard) is the best choice. This flea medication contains an adulticide; whereas, pyriproxyfen and Lufenuron are only insect growth regulators. Spinosad should never be used with extra-label doses of Ivermectin and is probably why this client discontinued flea medications in the first place. Permethrin is an excellent flea medication, as it is a repellent and adulticide, but it is toxic to cats. Fipronil is toxic to rabbits.

141

A 5-year old intact male Pomeranian presents for slowly progressing alopecia of the trunk that is sparing the head and limbs. Skin cytology revealed no infectious organisms or inflammatory cells. CBC and chemistry panel were unremarkable. You explain to the owner that you are most concerned about an endocrinopathy and would like to pursue further endocrine testing. Thyroid panel and ACTH stimulation test are both within reference range. Given the history, what is the best treatment option?

a. Trilostane

b. Mitotane

c. Growth hormone supllementation

d. Castration

e. Levothyroxine

d. Castration

Based on the history and ruling out other endocrinopathies this patient likely has hair cycle arrest (Alopecia X). The pathogenesis of this disease is not known. This condition is common in Pomeranians, Chow Chows, Alaskan Malamutes, Toy Poodles, and Samoyeds. The most common clinical signs are truncal alopecia and hyperpigmentation. The treatment of choice (if the dog is intact) is to neuter; however, it is not uncommon to see a relapse in clinical signs 1-2 years after neutering. Melatonin may help new hair to grow if a relapse occurs. Trilostane, mitotane, and growth hormone supplementation have been tried with varying success. Levothyroxine is a thyroid supplement and would not be indicated.

142

A 2-year old female spayed miniature poodle presents for a focal area of alopecia (5cm in diameter) on the right caudal-lateral thigh. The area is also hyperpigmented. The owner explains that the original lesion was a nodule, but over the last couple of months the hair started to fall out and the skin turned dark. The owner reports that otherwise the dog has been doing well. You ask if any topical medications or treatments have been done on or near the area. The owner reports that she has not done any treatments. The only medications the dog has received are her yearly vaccines (4 months ago) and heartworm preventative. Based on the history and physical exam findings, what are you most concerned about and what diagnostic would you like to perform?

a. You are concerned about a vaccine reaction; biopsy

b. You are concerned about an allergic reaction; food trial

c. You are concerned about an autoimmune disease; biopsy

d. You are concerned about an endocrinopathy; thyroid panel

a. You are concerned about a vaccine reaction; biopsy

The lesion is highly suggestive of a vaccine reaction; particularly post-rabies vaccination panniculitis (inflammation of the sub-cutaneous) due to location and description of the lesion. Rabies vaccine is often given in the right hind limb.

Initially, this condition presents with a nodule where the vaccine occurred and then complete alopecia occurs 1-3 months afterwards. Many times there is a long delay between vaccination and clinical signs (up to 6 months). Lesions usually resolve on their own, but use of pentoxifylline or prednisone can be effective. Definitive diagnosis would require a skin biopsy.

An allergic reaction or endocrinopathy is less likely since the lesion is focal. Endocrinopathies usually result in bilaterally symmetrical alopecia. Hair loss due to allergies is usually a result of pruritus, which was not mentioned in the history. This would be an atypical location and lesion for an autoimmune condition.

143

What is the most appropriate method for diagnosis of dermatophytosis in order to develop the best treatment and management recommendations?

a. White colony growth and red color change at 5 to 7 days

b. Analysis of endothrix or ectothrix spores in hairs

c. Wood's lamp fluorescence of hair

d. Microscopic examination of macroconidia

d. Microscopic examination of macroconidia

Proper management of dermatophytosis requires identification of genus and species, which can only be done from microscopic examination of macroconidia. Only about 50% of Microsporum canis strains fluoresce with ultraviolet light (Wood's lamp). Microsporum gypseum and Microsporum canis can both present as white colony growth with a pH change at 5 to 7 days, but require different management strategies. The source of M. gypseum is soil; the ultimate source of M. canis is a potentially asymptomatic cat.

144

A 5-month-old Shih Tzu presents for greasy skin, pruritus, and mild hair loss of the face. You perform skin cytology and no bacteria or yeast are observed. What test, that is part of the minimum dermatological database, would you perform next?

a. Complete blood count

b. Diet trial

c. Intradermal skin test

d. Skin scrape

e. Bacterial culture

d. Skin scrape

Demodex injai typically causes greasy seborrhea, especially on the face and dorsal trunk. Terriers and Shih Tzus may be predisposed. Some dogs may be pruritic. This mite is long and slender when compared with Demodex canis.
A diet trial and intradermal skin test may be indicated in the future if the skin scrape is negative. A bacterial culture may be needed if bacteria were seen on cytology. There is no indication to perform a CBC. None of the other tests would be considered part of a dermatological database

145

A 5-month old intact female mixed breed presents to your hospital for the progressive lesions seen on the image provided. The owner described the lesions as initially being papules and vesicles which eventually ruptured. Recently, the owner has also noticed that the muscles of the face appear to be atrophied. Muscle and skin biopsies were performed which came back supportive of a diagnosis of dermatomyositis. Which of the following medications is not useful for the treatment of this condition?

a. Cyclosporine

b. Prednisone

c. Pentoxifylline

d. Hycodan

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d. Hycodan

Dermatomyositis is a relatively unusual condition that results in skin lesions as well as myositis. The skin lesions initially appear as papules and vesicles which then rupture, ulcerate, and may progress to crusty alopecic lesions. The myositis sets in a little later and atrophy of the temporalis muscle is often seen. In more severe cases the muscles of the distal extremities become involved and megaesophagus may be observed. Since muscle changes usually lag, other diagnostic tests such as a skin scraping and cytology are performed first to rule out other common conditions. The condition has a variable prognosis as the clinical signs may wax and wane. Medical management usually consists of pentoxifylline, prednisone, and cyclosporine. Prednisone and cyclosporine serve as immunomodulatory medications. Pentoxifylline is used to help improve bloodflow. Hycodan contains hydrocodone and is used as a cough suppressant.

146

A 1 year old German Shepherd presents for pruritus and folliculitis. The owner explains the pruritus began around 7 months of age and seems to be progressive. The patient is on monthly flea control and heartworm prevention medications. Examination reveals a generalized folliculitis over the dorsal trunk, thorax, and abdomen. You perform skin cytology, skin scrape, and dermatophyte culture. The skin scrape and dermatophyte culture were negative. Skin cytology reveals 4+ cocci and degenerative neutrophils. CBC/Chem and thyroid panel were within normal limits. You explain to the owner that the dog has a superficial bacterial dermatitis that is secondary to an underlying allergy. What is your next step?

a. Systemic antibiotics for 3-4 weeks and intradermal skin test

b. Systemic antibiotics for 3-4 weeks and start a diet with a novel protein diet

c. Systemic antibiotics for 1-2 weeks and start a diet trial with a novel protein diet

d. Topical antibiotics and intradermal skin test

e. Systemic antibiotics for 2-3 weeks and intradermal skin test

b. Systemic antibiotics for 3-4 weeks and start a diet with a novel protein diet

Superficial bacterial infections require antibiotics for at least three weeks. Deep infections require antibiotics for 6-8 weeks. The decision to stop antimicrobial therapy should ideally be based on clinical signs. The general rule is to stop antibiotics 2 weeks after clinical resolution. In practice, this can be difficult because it would require multiple re-checks. Topical therapy with an antimicrobial shampoo can be beneficial, but this infection appears generalized and severe; therefore systemic antibiotic therapy is warranted.

As with any bacterial infection there is usually an underlying cause. The logical next step would be to perform a diet trial and rule out food allergy before work-up of environmental allergies. Environmental allergy is a diagnosis of exclusion and flea, food, and contact allergies must be ruled out before a diagnosis of environmental allergies is made. Additionally, intradermal testing cannot determine if a patient has environmental allergies or not, since normal dogs will also test positive. Additionally, this dog most likely has a food allergy based on the age of onset of clinical signs. Food allergy occurs usually before a year of age whereas environmental allergies occur after 9 months to 1 year of age.

147

The best diagnostic test to differentiate pituitary dependent hyperadrenocorticism from adrenal dependent hyperadrenocorticism in dogs is which of the following

a. Serum cortisol

b. Low-dose dexamethasone suppression test

c. Urine cortisol : creatinine ratio

d. High-dose dexamethasone suppression test

d. High-dose dexamethasone suppression test

HDDST will suppress cortisol secretion in about 75% of PDH patients 3-6 hours post dexamethasone administration. Cortisol secretion does not become suppressed with dexamethasone administration with adrenal dependent hyperadrenocorticism. If cortisol secretion is suppressed with a HDDST, PDH is diagnosed. If cortisol is not suppressed, there is a 50-50 chance that the hyperadrenocorticism is due to PDH or an adrenal tumor.

LDDST will suppress cortisol secretion in approximately 65% of pituitary dependent hyperadrenocorticism patients. The urine cortisol:creatinine ratio measures the significance of urine cortisol concentration and may be increased with both PDH and ADH. Serum cortisol levels may be affected in many different situations such as stress; therefore they are an unreliable indicator of disease. An elevated serum cortisol level will not differentiate between PDH and ADH.

148

What test should be run to monitor the efficacy of treatment for an Addisonian dog being treated with supplemental mineralocorticoids and glucocorticoids?

a. ACTH stimulation test

b. Urine cortisol creatinine ratio

c. Serum sodium and potassium

d. Serum chloride and phosphorus

e. Resting cortisol level

c. Serum sodium and potassium

Addisonian patients deficient in mineralocorticoids will usually exhibit the classic findings of hyponatremia and hyperkalemia. Monitoring serum sodium and potassium concentration while treating with exogenous mineralocorticoids is the best way to determine if the level and frequency of dosage is adequate for the patient.

An ACTH stimulation test can be used to monitor the efficacy of treatment of a patient with Cushing's disease, but does nothing for an Addisonian.

149

Which of the following is not a classic bloodwork finding for a dog with hypoadrenocorticism?

a. Anemia

b. Hypoglycemia

c. Hyperkalemia

d. Azotemia

e. Hypernatremia

e. Hypernatremia

The classic laboratory finding for an Addisonian includes hyponatremia, hyperkalemia, azotemia, anemia, acidosis, hypoglycemia, and of course a low resting cortisol level or low ACTH stimulation test result.

150

Which of the following statements is true regarding a 6-year old Cocker Spaniel that has polyuria, polydipsia, and blood glucose consistently around 160 mg/dl (normal 76-119 mg/dl)?

a. A urinalysis should be run and will likely show large amountsof glucose and ketone in the urine

b. The polyuria and polydipsia are not likely caused by diabetes mellitus.  Further diagnostic tests should be pursued to look for the cause of polyuria and polydipsia

c. The dog has diabetes mellitus.  The polyuria is caused by osmotic diuresis of glucose spilling into the urine, and the polydipsia is secondary to the polyuria

d. The dog has diabetes mellitus. The polyuria is caused by the kidneys being refractory to antidiuretic hormone. The polydipsia is secondary to the polyuria.

b. The polyuria and polydipsia are not likely caused by diabetes mellitus.  Further diagnostic tests should be pursued to look for the cause of polyuria and polydipsia

In a dog with normal kidneys, glucose does not begin to spill into the urine until the blood glucose is around 180 mg/dl. In a cat, glucose does not begin to spill into the urine until the blood glucose reaches between 200-280 mg/dl. Another cause for the PU, PD should be sought in this patient. When the blood glucose is high enough to spill into the urine, the polyuria seen is caused by an osmotic diuresis resulting from the osmotic pull of the glucose in the urine. The kidneys are not refractory to antidiuretic hormone with DM.

151

A 9-year old male, neutered German Shepherd dog is presented to your clinic for evaluation of tenesmus, tail chasing, and hematochezia. Malodorous mucopurulent discharge is noted near his anus. On examination, you find multiple ulcerations around his perineum. Rectal examination reveals reduced anal tone and mucosal thickening. What are your treatment recommendations for this dog?

a. Initiate broad-spectrum antibiotics to treat for an infected anal gland abscess

b. Initiate therapy with cyclosporine

c. Initiate chemotherapy with the alkylating agent, melphalan, as this is the treatment of choice ofr anal sac adenocarcinoma

d. Surgically correct with a 360-degree anoplasty

e. Initiate therapy with metronidazole

b. Initiate therapy with cyclosporine

The signalment, history and clinical signs are most consistent with a perianal fistula. Although the pathogenesis is not fully understood, this disease is thought to be primarily immune-mediated. The treatment of choice for perianal fistula is medical management with cyclosporine, as resolution is achieved in greater than 65% of dogs. Surgical correction may lead to fecal incontinence or stricture formation, however surgery for removal of the anal sacs in combination with cyclosporine has recently shown promise.

If this was an anal gland abscess, lancing the abscess and drain placement with systemic antimicrobial therapy would be indicated. If you suspected this to be a cancerous process, a minimum database including CBC, chemistry, thoracic radiographs and abdominal ultrasound are recommended for disease staging. The treatment of choice for anal sac adenocarcinoma is surgical resection, followed by adjunct therapy.

152

What is the treatment of choice for perianal fistulas?

a. Immunosuppressive drugs

b. Intestinal prokinetic drugs

c. Antibiotic therapy

d. Radiation therapy

 

a. Immunosuppressive drugs

Antibiotics may reduce symptoms temporarily but will not cure perianal fistulas. Surgery used to be the treatment of choice, but it carries a guarded prognosis due to the risk of fecal incontinence. Perianal fistulas are an immune mediated disease, and medical management with immunosuppressive therapy, perhaps with cyclosporine, is now the initial treatment of choice. However, a combination of surgery and immunosuppressive therapy is not uncommon. German shepherds are predisposed to development of perianal fistulas.

153

A 6-week old mixed breed dog acquired from a shelter presents for diarrhea, increased respiratory effort, and seizures. You suspect the puppy has distemper. What is the definitive diagnostic test for canine distemper?

a. Immunofluorescent assay on affected epithelium

b. Enamel hypoplasia

c. Hyperkeratosis of foot bads

d. The combination of gastrointestinal, respiratory, and neurologic clinical signs

e. Detection of virus via serology

a. Immunofluorescent assay on affected epithelium

Although the clinical signs are supportive for distemper, the definitive diagnosis is examination of blood or tissue by immunofluorescent assay. This can be performed on tracheal, vaginal, respiratory, or other epithelium. These samples may be negative if the dog is only showing neurologic signs or if a circulating antibody is present. The diagnosis can then be made by serology for distemper IgM or increased CSF to serum virus specific IgG. In addition, a distemper PCR test is now available and is performed on swabs of ocular or nasal discharge. The test can have false positives in some vaccinated animals; however, animals showing signs consistent with distemper that are PCR positive should be considered likely infected with distemper.

154

An obese, sedentary, female Bichon Frise of 5 months of age walks into your clinic as a result of having mucous-laden diarrhea of one week duration. You perform a gram stain of the feces and visualize "gull shaped" gram negative rods. What is the most likely diagnosis?

a. Cryptosporidium

b. Clostridium difficile

c. Campylobacteriosis

d. Salmonellosis

c. Campylobacteriosis

This is a gram negative motile, thin, S shaped or gull shaped rod. It can occur singly, in pairs or in chains. C. jejuni is most commonly isolated. You can also isolate this organism with fresh fecal swabs streaked onto Campylobacter blood agar plate which grows in an oxygen-reduced atmosphere in 3-4 days. Salmonella is a gram negative bacillus. C. difficile is a gram positive rod. Cryptosporidium is a coccidian parasite. Fun Fact: Kids with puppies are 16 times more likely to acquire campylobacteriosis.

155

A 4 year old male Akita presents with a foreign body obstruction. You perform an intestinal resection and anastomosis surgery due to the compromised appearance of the intestine at the foreign body site. The dog recovered well after surgery. Five days post-operatively, she presents again with a history of inappetance and has a 104.8 F (40.4 C) temperature. What is the best diagnostic test to confirm your clinical suspicion?

a. Complete blood count and serum chemistry

b. Abdominal ultrasound

c. Serum lactate

d. Thoracic radiographs

e. Abdominocentesis

e. Abdominocentesis

You should be highly suspicious of leakage at the surgery site and resultant septic peritonitis. The most common time for anastomosis failure is 3-5 days postoperative. This is due to the degradation of fibrin at the site prior to deposition of sufficient collagen.

Abdominocentesis would likely reveal a septic inflammatory process, confirming your clinical suspicion with the finding of of intracellular bacteria. A CBC and chemistry are helpful adjunct diagnostic tests but are not specific for septic peritonitis. An abdominal ultrasound would not distinguish between post-operative abdominal fluid and/or free gas and a septic effusion. Serum lactate, although helpful, is also not specific for sepsis. Thoracic radiographs could be useful to assess for less likely complications such as aspiration pneumonia.

156

Which of these findings is most supportive of a diagnosis of HGE (hemorrhagic gastroenteritis)?

a.  Packed cell volume of 45%
b. Total solids of 6.0

c. Chronic hemorrhagic diarrhea

d. Positive fecal test for coccidia

b. Total solids of 6.0

HGE is characterized by acute onset of hemorrhagic diarrhea accompanied by marked hemoconcentration. HGE can be due to a hypersensitivity reaction in the intestines or from Clostridium perfringens enterotoxin. It usually affects small dogs such as Miniature Poodles and Miniature Schnauzers. They develop a raspberry jam-like diarrhea, vomiting, and abdominal pain. The key findings are a high PCV of 55-60 and normal total protein that is not as high as would be expected from the degree of hemoconcentration, probably due to protein loss into the intestine.

157

A 5-year old male castrated English Springer Spaniel presents for a dental exam. The dog has a history of aggressive chewing on tennis balls and frisbees. The oral exam reveals brown, worn-down incisors, canines, and premolars. The dog is otherwise normal and healthy. What is the cause for the teeth turning brown?

a. Excessive chewing has predisposed the teeth to infection.  The brown coloration is a sign of bacterial infection

b. The dog was probably given tetracycline antibiotics as a puppy, which causes a permanent brown discoloration of teeth

c. The teeth are brown due to the formation of tertiary dentin, which stains easily

d. The excessive chewing has worn away the enamel of the teeth.  The underlying dentin is naturally brown.

c. The teeth are brown due to the formation of tertiary dentin, which stains easily

Aggressive chewing of things like rocks, tennis balls, cage bars, etc. causes abrasion of dentin. Tertiary dentin, which is produced as a response to the wearing of the teeth, stains easily. Tertiary dentin will usually prevent the exposure of the pulp cavity unless its production cannot keep up with its rapid wear.

158

Which of these is an important nutritional goal in the management of struvite urolithiasis?

a. Maintaining urine specific gravity of <1.020

b. Increasing magnesium in the diet

c. Increasing dietary protein

d. Maintaining a urine pH of 8 to 8.5

a. Maintaining urine specific gravity of <1.020

An important principle in management of any patient with urolithiasis is to maintain dilute urine so that solutes do not concentrate to the degree that they form precipitates that lead to stone formation. Struvite stones (magnesium ammonium phosphate) tend to form in alkaline urine so ideal urine pH for struvite stone formers is usually around 6.5. Other principles of management are to decrease urea in the urine, often done by moderate protein restriction and to decrease the minerals involved (magnesium and phosphate). Finally, a key element in struvite stone formation is the presence of a urinary tract infection, particularly with urease-producing microbes, most notably staphylococcus and proteus. Monitoring, preventing, and treating UTIs is an important aspect of management of these patients.

159

What is the difference between an incomplete and a complete cataract?

a. An incomplete cataract occurs after the development of a complete cataract due to degradation of the lens fibers

b. Both are diffuse changes throughout the lens, but the animals can see through an incomplete cataract.

c. An incomlete cataract is in the center of the lens and is a normal aging change.  A complete cataract involves the entire lens and is abnormal

d. An incomplete cataract is a focal change, and a complete cataract is diffuse throughout the lens.

b. Both are diffuse changes throughout the lens, but the animals can see through an incomplete cataract.

An incomplete cataract is not completely opacified and a tapetal reflection can be seen through it. The animal can see through an incomplete cataract, albeit probably not as clearly as through a normal lens. A complete cataract is a completely opacified lens that cannot be seen through and through which a tapetal reflection cannot be seen. A focal cataract is referred to as an incipient cataract. The normal aging change to the center of the lens is nuclear sclerosis. Degradation of lens proteins after developing a cataract is termed a resorbing cataract.

160

The Pug in the picture presents on emergency. What is the likely cause of this condition?

a. Intoxication

b. Glaucoma

c. Infection

d. Immune mediated disease

e. Trauma

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e. Trauma

Traumatic proptosis is very common in brachycephalic breeds and is the lesion in the picture.

161

You examine a dog with bilateral blepharospasm, mucoid ocular discharge, and 360 degree corneal vascularization. What test will most likely give you a diagnosis as to the cause of these signs?

a. Schirmer tear test

b. Tonometry

c. Fundic exam

d. Fluorescein dye stain

a. Schirmer tear test

A mucoid ocular discharge is the primary sign of keratoconjunctivitis sicca. A Schirmer tear test measures the amount of aqueous tear film being produced. In KCS, it should measure very low. The Fluorescein dye stain would check for disruption of the corneal layers such as a corneal ulcer. Tonometry would measure the intraocular pressure and look for diseases such as uveitis or glaucoma. The Fundic exam evaluates the retina and optic nerve for abnormalities.

162

You are examining a 12-year old male castrated mixed breed dog with progressive exophthalmos and third eyelid protrusion of the left eye over the past month as shown here. On palpation, no pain is elicited but the eye does not retropulse. The owner reports that otherwise the dog has been behaving normally, and physical exam is otherwise unremarkable. What is the most likely diagnosis?

a. Retrobulbar abscess

b. Intraocular neoplasia

c. Orbital neoplasia

d. Endophthalmitis

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c. Orbital neoplasia

These are the typical signs of orbital neoplasia, which is somewhat common in older dogs. Infections are usually accompanied by more systemic signs and localized pain and erythema. Endophthalmitis and intraocular neoplasia would not cause exophthalmos but would manifest with intraocular signs.

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163

You are examining a 3-year old female Miniature Poodle whose owner complains that she has been bumping into things more and more recently, especially at night. On fundic examination, you note tapetal hyperreflectivity, gray, vermiform lines on the fundus, retinal vascular attenuation, and a pale optic disc. Which of these choices is the most likely cause of her problem?

a. Glaucoma

b. Progressive Retinal Atrophy (PRA)

c. Taurine Deficiency

d. Sudden Acquired Retinal Degeneration Syndrome (SARDS)

 

b. Progressive Retinal Atrophy (PRA)

The correct answer is PRA. Progressive retinal atrophy, sometimes called progressive retinal degeneration is an inherited retinal disease seen in several breeds but most notably Toy and Miniature Poodles. Age of onset is variable, but signs are usually night blindness progressing to complete blindness due to loss of rods prior to cones. Retinal lesions are classically the ones described in this case. It is differentiated from SARDS by the clinical course and the fact that there are no retinal lesions in acute SARDS. You could see similar retinal lesions from glaucoma but would expect more clinical signs and you wouldn't have night blindness progressing. Taurine deficiency causes retinal lesions in cats not dogs, and they have a different appearance.

164

You have been managing a 7-year old male Cocker Spaniel for immune-mediated hemolytic anemia and recurrent urinary tract infections with prednisone and trimethoprim sulfa antibiotics. He now presents to you for the ocular abnormalities visible in the photo. What test is most likely to confirm your tentative diagnosis?

a. Dilated fundic exam

b. Corneal biopsy

c. Schirmer tear test

d. Tonometry

e. Pupillary light response

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c. Schirmer tear test

This dog has a severe mucoid ocular discharge and corneal changes that are most consistent with keratoconjunctivitis sicca (dry eye). The history of TMS antibiotics is a likely etiology. The diagnostic test of choice for KCS is a Schirmer tear test. The other choices are not specific for the diagnosis of this condition.

165

Keratoconjunctivitis sicca, as seen in the image, comes from an abnormality in which of these structures?

a. Nasolacrimal duscts

b. Meibomian gland

c. Lacrimal galnd and gland of the 3rd eyelid

d. Conjunctival goblet cells

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c. Lacrimal galnd and gland of the 3rd eyelid

KCS comes from a decrease of the aqueous portion of the tear film. This is produced by the lacrimal gland and the gland of the 3rd eyelid. Remember, there are three layers of the tear film. The mucous portion lies against the cornea and keeps the tear film adhered to it. This is made by conjunctival goblet cells. The aqueous portion has nutritional and immunologic factors and is in the middle. It is produced by the lacrimal gland and the gland of the 3rd eyelid. The lipid portion of the tear film is the most outer part, and it allows for even spreading and prevents evaporation of tears. It is produced by the meibomian glands.

166

What changes are seen on electroretinogram (ERG) with sudden acquired retinal degeneration syndrome (SARDS) in dogs?

a. Flat-line ERG (no response)

b. Decreased ERG amplitude (weakened response)

c. Normal ERG amplitude

d. Increased ERG amplitude (exaggerated response)

a. Flat-line ERG (no response)

By definition, an animal with SARDS has a flat-line ERG from day 1 of onset of the condition

167

Which of these is usually the cause of glaucoma as depicted in this dog?

a. Decreased outflow of aqueous

b. Increased production of aqueous

c. Increased outflow of aqueous

d. Increased production of vitreous

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a. Decreased outflow of aqueous

Glaucoma is an increase in IOP which is dependent on production of aqueous and outflow of aqueous. Clinical increases are always from decreased outflow although treatment can be aimed at either increasing outflow or decreasing production of aqueous.

 

168

Lens removal is strongly recommended for several conditions. Which of these conditions necessitates immediate lens removal?

a. Incipient cataract

b. Posterior lens luxation

c. Anterior uveitis

d. Porgressive retinal atrophy

e. Anterior lens luxation

e. Anterior lens luxation

Lens removal is indicated in cases of anterior lens luxation because they usually cause discomfort and usually cause uveitis and glaucoma. Posterior lens luxations are usually innocuous and can be left on the floor of the vitreous cavity. An incipient cataract should only have a minor effect on vision and does not necessitate lens removal. Uveitis and retinal atrophy will not be improved by lens removal. Keep in mind that an argument could be made for removal of the lens in both posterior lens luxation and the cataract; however, the best answer choice is still anterior lens luxation.

169

Dogs with which endocrinopathy have an increased incidence of sudden acquired retinal degeneration syndrome (SARDS)?

a. Addison's

b. Hyperadrenocorticism

c. Hyperparathyroidism

d. Hypothyroidism

e. Diabetes mellitus

b. Hyperadrenocorticism

SARDS is frequently seen in middle-aged obese spayed females and often have signs of PU/PD and polyphagia as well as increased liver enzymes and cholesterol. The reason for the association of Cushing's disease and SARDS is poorly understood.

170

The image of the eye below is from a canine patient diagnosed with keratoconjunctivitis sicca (KCS). This condition causes a decrease in tear production which then results in the classic changes observed in this image. Which of the following is not an etiology of the disease?

a. Long-term atropine administration

b. Sulfonamide toxicity

c. Immune mediated

d. Penicillin toxicity

 

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d. Penicillin toxicity

In canine patients, the most common cause of KCS is immune mediated. This is why these patients are treated with cyclosporine, a t-cell modulator. Penicillins have not been documented to result in KCS. Sulfonamide containing antibiotics, such as TMS have been shown to cause KCS in some patients. Long-term atropine administration has also been shown to result in KCS. Atropine is a parasympatholytic and will result in decreased tear production. Etodolac has also been associated with KCS in dogs. The corneal pigmentation seen is a nonspecific response to chronic irritation or inflammation. There is also evidence of corneal vascularization which occurs as part of the inflammatory and healing response.

171

Which of these are you least likely to see in acute glaucoma as depicted in this dog?

a. Corneal edema

b. Pain

c. Buphthalmos

d. Episcleral injection

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c. Buphthalmos

Acute glaucoma can be a very painful condition characterized by epiphora, episcleral injection, corneal edema, and sometimes mydriasis. Buphthalmos, or an enlarged globe, does not usually occur with an acute rise in IOP and is seen more chronically.

172

A 6-week old male intact puppy has presented to your clinic after being bitten 4 days ago. On physical examination, there is a moderate amount of purulent discharge noted from the bite wound on the left antebrachium. The wound is approximately 2 cm in length. Which antibiotic is LEAST appropriate for this patient?

a. Metronidazole

b. Cephalexin

c. Penicillin

d. Doxycycline

 

d. Doxycycline

Doxycycline can result in delayed bone growth and discoloration of the teeth in young growing animals and is thus contraindicated. The other medications listed do not have a direct effect on young growing animals and are safe to administer; however, one must consider the likely pathogen present in the wound, what type of susceptibility pattern it has, as well as the likely penetration of your antibiotic into the area where you want it to exert its effect prior to making a choice.

173

Two months ago, you prescribed one of your feline patients a course of pradofloxacin (Veraflox), a fluoroquinolone antibiotic, to treat an abscess. The owner of the cat also owns a small dog who now has pyoderma with Staphylococcus susceptible to fluoroquinolones. She asks you if she can use the remaining pradofloxacin for her dog that she has left over from her cat. What should you tell her?

a. Pradofloxacin is not for use in dogs due to bone marrow suppression

b. Pradofloxacin is not for use in dogs as it has been associated with development of acute blindness

c. Pradofloxacin is not a good choice for a skin infection because it is does not achieve adequate levels in the skin

d. Pradofloxacin is a good choice for her dog's skin infection

e. Pradofloxacin is not for use in dogs as it has been associated with renal toxicity

a. Pradofloxacin is not for use in dogs due to bone marrow suppression

Pradofloxacin (Veraflox) is an orally administered, liquid fluoroquinolone antibiotic that was FDA approved in 2012 for use in cats to treat skin infections (wounds and abscesses) caused by Pasteurella multocida, Streptococcus canis, Staphylococcus aureus, Staphylococcus felis, and Staphylococcus pseudointermedius. The drug is not for use in dogs and it has been shown to cause bone marrow suppression resulting in severe thrombocytopenia and neutropenia.

Enrofloxacin has been associated with retinal degeneration in cats, particularly at high doses and is used with caution for this reason.

 

174

You are treating an 8-year old mix breed terrier for ventricular tachycardia post splenectomy. You determine that you've given too much lidocaine to the patient. What clinical signs or laboratory findings are you most likely to see initially?

a. Bradycardia and hypotension

b. Muscle tremors and seizures

c. Methemoglobinemia

d. Diarrhea

e. Increased respiratory rate and difficulty breathing

b. Muscle tremors and seizures

Early clinical signs associated with lidocaine toxicity include neurological symptoms such as seizures and tremors. Nausea and vomiting may occur, but is usually transient. Cardiovascular and respiratory depression can also occur, but usually later on in the course of clinical signs.

175

You ask your technician to give a 1 ml/kg dose of lidocaine to a dog that is having ventricular premature complexes. You realize after it is too late that she miscalculated the dose and gave 10 times what you asked for. What is the most common early sign of lidocaine toxicity in dogs?'

a. Peripheral neuropathy

b. Central nervous system depression

c. Apnea

d. Profound bradycardia

e. Anaphylaxis

b. Central nervous system depression

n dogs, toxicity of lidocaine is manifest primarily as CNS signs. Drowsiness or agitation may progress to muscle twitching and convulsions at higher doses. This occurs before respiratory or cardiac depression. Hypotension may develop if an IV bolus is given too rapidly.

Cats are more sensitive to lidocaine toxicity and may show cardiac suppression and CNS excitation.

176

What adverse reaction are Dobermans predisposed to when using trimethoprim-sulfa?

a. Gastrointestinal ulcer formation

b. Vestibular disease

c. Hypersensitivity reaction

d. Pancreatitis

 

c. Hypersensitivity reaction

Doberman Pinschers are more susceptible to hypersensitivity reactions from sulfa drugs as compared to other breeds. Type III reactions can result in immune complex disease which can cause arthritis, nephritis, and uveitis. Other possible side effects from this class of antibiotics that are not specific to the Doberman include KCS, hepatitis, and blood dyscrasias.

177

You have a 6-year old female spayed Cocker Spaniel with immune mediated hemolytic anemia (IMHA), and would like to start her on azathioprine and prednisone. Which one of the following is NOT a reported possible side effect of azathioprine?

a. Acute pancreatitis

b. Nephrotoxicity

c. Gastrointestinal upset

d. Bone marrow suppression

e. Hepatotoxicity

b. Nephrotoxicity

Nephrotoxicity is not a reported side effect of azathioprine. All others on this list have been reported as side effects or have been associated with the use of azathioprine. GI upset is the most common of the 4 listed, although it is still relatively infrequent. The other 3 listed side effects are uncommon, but can be life-threatening, so they must be discussed with the owner before starting treatment.

Cats are more sensitive to these side effects than dogs because of a deficiency in thiopurine methyltransferase, the enzyme used to metabolize azathioprine. Azathioprine should be used with caution, if at all, in cats.

178

An 11-year old male castrated Border Collie presents in laterally recumbency. The owners noticed he had been limping on his right front leg for the past three days. He has free access to the backyard, but did not come back to the house this morning for breakfast and the owners found him outside laterally recumbent. On physical exam, he has extensor rigidity of all four legs with extension of his head and neck (as seen in the image). His lips and ears are contracted and pulled back. There is a wound between digits 2 and 3 on the right forelimb with a draining tract. Which of the following should be discussed with the owner?

a. Confirmatory diagnosis involves finding the exotoxin from Clostidium botulinum in serum, feces, vomit, or food samples

b. Tetanus antitoxin will help to reverse the clinical signs

c. Tetanus antitoxin can cause anaphylaxis

d. Removal of the tick will help reverse clinical signs

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c. Tetanus antitoxin can cause anaphylaxis

The facial contraction and smirk is a characteristic sign of tetanus. Tetanus is caused by the neurotoxin produced by Clostridium tetani. This bacteria enters the body through a wound and begins producing tetanospasmin, a potent neurotoxin that blocks GABA release at the motor end plate and causes sustained muscle contraction.

Treatment involves wound debridement, sedation, antibiotics, and minimizing external stimuli as these animals are hyperesthetic. Tetanus antitoxin is given after an initial test dose to monitor for anaphylaxis. Antitoxin prevents further toxin binding but does not affect already bound toxin so it helps decrease progression of clinical signs but will not reverse the signs present.

Tick paralysis starts with hind limb weakness which progresses to a stiff forelimb gait and flaccid paralysis. Patients will improve quickly after removal of the tick. Clostridium botulinum causes botulism which is characterized by lower motor neuron paresis/paralysis starting in the pelvic limbs and progressing to quadriplegia. There is decreased muscle tone in all limbs.

179

Which of the following is not true about doxycycline used in dogs?

a. It can cause discoloration of teeth and thin enamel in puppies

b. It can cause gastrointestinal upset

c. It can cause esophageal stricture formation if the drug remains in the esophagusfor an extended time period

d. It can cause cartilage abnormalities in growing puppies

d. It can cause cartilage abnormalities in growing puppies

Fluoroquinolone antibiotics such as enrofloxacin can cause cartilage formation abnormalities in growing animals. Doxycycline is a tetracycline antibiotic that can cause esophageal stricture formation if it remains in the esophagus for an extended period of time. A small amount of food or water is usually given after the pill to ensure the tablet is not lodged in the esophagus. It can also cause teeth abnormalities in growing animals and often causes GI upset.

180

Which of the following is not an appropriate recommendation for treating an animal that ingested anticoagulant rodenticide within the past 4 hours?

a. Administer activated charcoal

b. Induce emesis

c. Give Vitamin K1

d. Give plasma

d. Give plasma

It takes at least a few days for anticoagulant rodenticides to cause prolonged bleeding times and clinical hemorrhage. This could likely be prevented with early intervention with decontamination and Vitamin K1 administration. A plasma transfusion at this stage is unnecessary and should be reserved for patients that have prolonged bleeding times.

181

In dogs, large doses of epinephrine cause which of the following?

a. Increase in arterial blood pressure, decrease in cardiacccontractility, bronchodilation

b. Increase in total peripheral resistance, increase in cardiac contractility, bronchodilation

c. Increase in arterial blood pressure, increase in cardiac output, bronchoconstriction

d. Decrease in total peripheral resistance, increase in cardiac contractility, bronchodilation

b. Increase in total peripheral resistance, increase in cardiac contractility, bronchodilation

Epinephrine is an alpha- and beta-adrenergic stimulant which causes peripheral vasoconstriction, increase in total peripheral resistance, increase in cardiac contractility and cardiac output, and bronchodilation. It is often used in cardiac arrests and anaphylactic shock. It is also found in some local anesthetic agents because of its vasoconstrictive effects, which prolongs effect of the anesthetic.

182

Zinc toxicity from ingestion of pennies minted after 1983 can cause which of the following?

a. Coagulopathy

b. Muscle spasms

c. Hemolysis

d. Thrombocytopenia

 

c. Hemolysis

Zinc causes a Heinz body anemia and hemolysis.

183

A client brings in her dog that recently ingested rodenticide. You check the box and see that the active ingredient is cholecalciferol. The dog appears clinically normal right now. What would you be concerned might happen if you do nothing at this time?

a. Development of coagulopathy

b. Development of organ mineralization

c. Development of liver failure

d. Development of neurologic signs

e. Development of intestinal perforation

b. Development of organ mineralization

Cholecalciferol (Vitamin D3) acts by becoming converted to calcitriol and increases calcium and phosphorus levels leading to mineralization of organs, especially the kidneys.

184

Which of the following is true about diltiazem?

a. Diltiazem speeds up the heart because it is a beta adrenergic agonist

b. Diltiazem slows the heart by antagonizing beta adrenergic receptors

c. Diltiazem speeds up the heart rate by increasing the influx of calcium into the myocardial cells

d. Diltiazem slows the heart by inhibiting the influx of calcium into the myocardial cells

 

d. Diltiazem slows the heart by inhibiting the influx of calcium into the myocardial cells

Diltiazem is a calcium channel blocker used to slow the heart to treat supraventricular tachycardias, hypertrophic cardiomyopathy, and hypertension.

185

The five-year old female Doberman Pincsher in the photo below whelped 8 puppies 4 weeks ago. She presents to you dehydrated and lethargic with temperature of 104.9 F (40.5 C). Her left inguinal mammary gland is hard, painful, hot, and reddish purple as seen in the image. What is the most likely diagnosis?

a. Hypocalcemia

b. Mammary carcinoma

c. Gynecomastia

d. Mastitis

e. Pyometra

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d. Mastitis

With the recent history of whelping, fever, and a firm, red, painful mammary gland, the most likely diagnosis is mastitis. The puppies should be removed and weaned and warm compresses applied to the gland to promote draining. Antibiotics that penetrate the barrier between the bloodstream and mammary gland should be considered such as trimethoprim-sulfa, clindamycin, and cephalosporins.

186

A 1-year-old female Doberman pinscher presents to you with vulvar swelling and bloody vaginal discharge as shown in the photograph. She has not been receptive to males. Which of the following is the most likely explanation?

a. Presentation of closed pyometra

b. Presentation of open pyometra

c. Normal appearance of proestrus

d. Normal appearance of diestrus

e. Normal appearance of estrus

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c. Normal appearance of proestrus

Vulvar swelling and edema occur with rising estrogen levels in proestrus. Bloody vaginal discharge occurs during proestrus due to diapedesis of blood from the engorged endometrium as blood travels through the cervix into the vagina. The bitch is not in estrus based on the lack of receptivity to males.

187

During which phases of the estrous cycle does the female dog attract male dogs?

a. Diestrus and estrus

b. Proestrus and estrus

c. Proestrus, diestrus, and estrus

d. Diestrus only

e. Estrus only

b. Proestrus and estrus

During both of these phases, the female attracts males but she will only stand to be mated during estrus.

188

A 10 year-old male intact Golden retriever presents to your hospital for sudden onset lethargy and decreased appetite. He has had no vomiting or diarrhea and the owners do not think he has gotten in to anything unusual. However, they do think he might sometimes deal with constipation, as they will often see him straining to defecate. On physical exam he is mildly dehydrated, with a fever and a soft non-painful abdomen. You are concerned and want to talk to your co-workers about the case. Before you go to talk to them, you remember the words of your internship mentor to never come talk to him about a case unless you have done both retinal and rectal exams on your patient. The retinal exam is normal, but you palpate an enlarged and irregular prostate, which seems to make your patient uncomfortable. Excitedly you realize you don't need to ask your colleagues for help as you now have a plan of your own. You send off a urine sample for culture. Which antibiotic do you reach for in the meantime?

a. Cephalexin

b. Metronidazole

c. Enrofloxacin

d. Cefpodoxime

e. Amoxicillin

c. Enrofloxacin

You should be suspicious for prostatitis in this patient. Your antibiotic choice should be based on culture and sensitivity results, but because your patient is sick you will want to start an antibiotic that has good penetration of the prostate until the culture results are back. Chloramphenicol, erythromycin, trimethoprim and fluoroquinolones are able to pass the blood-prostate barrier. Cephalexin and cefpodoxime are cephalosporins and may be effective if the blood-prostate barrier is disrupted, but they would not be the first choice.

189

The 6-year old 13 kg male cryptorchid Schnauzer in the image below presents for weakness, lethargy, intermittent epistaxis and melena of 1 week's duration. Physical findings include gynecomastia, a pendulous prepuce, symmetrical truncal alopecia, a palpable mid-abdominal mass, pale mucous membranes and a fever of 103.5 F (39.7 C). The dog's hematocrit is 14% (35-57%), with a total protein of 7.0 g/dl (5.4-7.5 g/dl). A blood smear reveals normocytic, normochromic anemia with a platelet count of 34,000/microliter (211,000-621,000/ul). The white blood cell count is 2,500/microliter (5,000-14,100/ul). Which of the following is most likely responsible for this dog's signs?

a. Cortisone deficiency

b. Thyroid hormone deficiency

c. Testosterone excess

d. Estrogen excess

e. Cortisone excess

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d. Estrogen excess

This dog's presentation should lead you to the presumptive diagnosis of an estrogen secreting tumor; likely a Sertoli cell tumor or seminoma. The dog was described as cryptorchid; dogs with cryptorchidism are prone to testicular tumors. The signs of male femininization such as gynecomastia and the signs of bone marrow suppression are most suggestive of estrogen toxicity.

190

Which of the following is the most likely cause of lymphoplasmacytic rhinitis as seen in this patient?

a. Parainfluenza virus-3

b. The specific etiology is still unknown

c. Canine adenovirus-2

d. Bartonella

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b. The specific etiology is still unknown

As the name implies, these patients have a mixed population of lymphocytes and plasma cells when biopsied. Many consider the condition to be an idiopathic immune-mediated disorder. PCR studies have been performed in affected patients in search of parainfluenza virus-3, canine adenovirus-2, Bartonella, and Chlamydophila. None of these agents were found to be a potential cause. Typical clinical signs include a history of unilateral or bilateral nasal discharge of several months duration. Large-breed dogs are more often affected and the age may vary.

191

What additional radiographic view in addition to a standard respiratory series should be taken to assess suspected intrathoracic tracheal collapse?

a. End inspiratory thorax

b. Oblique thorax

c. End expiratory thorax

d. Standing lateral thorax

c. End expiratory thorax

An end inspiratory view should be part of any normal thoracic radiograph series. An end-expiratory view is needed to document tracheal collapse in order to demonstrate intrathoracic tracheal narrowing because intrathoracic pressure is highest at end expiration which may worsen intrathoracic airway collapse. Standing lateral views are sometimes used to look for pleural effusion or pneumothorax. Oblique thorax projections are not used.

192

What is the most likely complication associated with the post-anesthetic recovery of the dog in the photograph receiving Clotrimazole?

a. Laryngeal inflammation

b. Seizure

c. Bacterial rhinitis

d. Aspiration pneumonia

 

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a. Laryngeal inflammation

Seizure is a possible sequela if the cribriform plate is compromised. If this were the case, the complication would likely be fatal. With severe swelling, the administration of corticosteroids and re-intubation is indicated. Sometimes these dogs may need to be intubated for days.

193

Lucy is an 11 year-old female spayed Labrador retriever presenting in acute respiratory distress after playing fetch on a hot summer day. On initial exam, Lucy is panting heavily and a loud stridor is audible. Upon further history-taking the owners tell you that Lucy's bark has changed over the past couple of months. What is the most common complication/side effect of the recommended treatment for Lucy's condition?

a. Kidney disease

b. Drooling

c. Tracheal collapse

d. Megaesophagus

e. Aspiration penumonia

e. Aspiration penumonia

Lucy's presentation is typical for a dog with laryngeal paralysis. The arytenoid cartilages fail to abduct during inspiration, resulting in upper airway obstruction. These patients often present with acute clinical signs even though the disease is chronic in nature. Surgical arytenoid lateralization (tie-back) is the treatment of choice but with the chronically opened airway, aspiration pneumonia can be a common side effect. If surgery is not an option, prednisone can be given to help reduce laryngeal inflammation.

194

A 5 year old female Weimaraner presents to your clinic with the presenting complaint of cough and difficulty breathing. On exam, the dog is subdued but responsive with a temperature of 103.3F (39.6 C), heart rate of 120 beats per minute and respiratory rate of 50 breaths per minute. You perform chest radiographs which are shown below. A CBC shows a hematocrit of 31% (35-57%), neutrophil count of 17,275/ul (2,900-12,000/ul), monocyte count of 1,484/ul (100-1,400/ul) and eosinophil count of 630/ul (0-1,300/ul). What is the treatment of choice?

a. Oxygen and durosemide

b. Oxygen and dexamethasone sodium phosphate

c. Oxygen, acepromazine, and hydromorphone

d. Oxygen, ampicillin, and enrofloxacin

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d. Oxygen, ampicillin, and enrofloxacin

This case and radiograph represent an example of a severe bronchopneumonia. While it would be appropriate to consider more diagnostics, such as a transtracheal wash for cytology and culture, you may have to make a choice without all of that information on your exam. For the information that you do have, aggressive and broad spectrum antimicrobial therapy with ampicillin and enrofloxacin is the best answer, with supportive care with oxygen as needed. Furosemide and oxygen would be the recommended treatments for a dog with congestive heart failure. Sedation and oxygen might be needed for a dog in severe distress from airway obstruction. Corticosteroids would not be an acceptable primary treatment for pneumonia.

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195

A 5-month old English Bulldog has difficulty breathing, stertor, and a cough. Which set of abnormalities is most likely present in this patient?

a. Tracheal collapse, laryngeal paralysis, and an elongated soft palate

b. Tracheal hypoplasia, stenotic nares, and an elongated hard palate

c. Tracheal hypoplasia, stenotic nares, and an elongated soft palate

d. Tracheal collapse, laryngeal paralysis, and an elongated hard palate

c. Tracheal hypoplasia, stenotic nares, and an elongated soft palate

Young brachycephalic dogs are often afflicted with a number of upper airway abnormalities collectively termed the brachycephalic airway syndrome. These are tracheal hypoplasia, stenotic nares, elongated soft palate, everted laryngeal saccules, and laryngeal collapse. It is easy to get these confused with tracheal collapse, which affects older toy and miniature dogs. The difference is that tracheal hypoplasia is a congenital narrowing of the trachea (Definition: lumen is less than twice the width of the third rib where they cross on radiographs), and collapsing trachea is an abnormality in the tracheal rings themselves.

196

Which of these groups is considered predisposed to developing nasal aspergillosis?

a. Dogs in large groups or kennels

b. Hunting dogs

c. Brachycephalics

d. Immunocompromised dogs

e. Dolichocephalic

 

e. Dolichocephalic

Aspergillus is typically a disease of healthy, apparently immunocompetent dogs that are young to middle-aged. Dolichocephalic breeds are overrepresented. Immunocompromise does predispose to development of disseminated aspergillosis. Being in a large group of dogs does not increase risk, as it is not a contagious disease. Aspergillus is fairly ubiquitous in the environment, and hunting dogs are probably not exposed significantly more than any other dog.

197

Following a routine spay, a dog exhibits moderate respiratory distress upon recovery that worsens over the next two hours. You take radiographs and see a bronchoalveolar pattern in the cranial lung field. What is your biggest concern?

a. The dog probably has pneumomediastinum from tracheal tube trauma

b. The dog probably has aspiration penumonia

c. The surgeon probably caused a pneumothorax during surgery

d. The dog is probably exhibiting an excitement phase from anesthesia

 

b. The dog probably has aspiration penumonia

Aspiration pneumonia is the most likely complication from this type of anesthesia and surgery. Coupled with the radiographic findings, it is the best choice. A pneumothorax from surgery or pneumomediastinum from tracheal tube trauma could both certainly occur but don't quite fit this scenario. If you were wondering how soon you would see respiratory signs from aspiration and radiographic signs, it can be very quickly.

198

Which of these is least likely to cause respiratory distress and an increase in respiratory rate in animals that are victims of smoke inhalation (as in smoke from a fire, not a cigarette)?

a. Thermal damage to the bronchi

b. Carbon monoxide inhalation

c. Laryngeal edema

d. Carbon dioxide inhalation

a. Thermal damage to the bronchi

Carbon monoxide inhalation is an important component of smoke inhalation morbidity as it leads to carboxyhemoglobin formation and displacement of oxygen. Carbon dioxide inhalation at high levels leads to severe acidosis, which leads to an increase in respiratory rate. Damage to the larynx from the heat causes edema and swelling, contributing to upper airway obstruction. The heat damage does not usually reach the level of the bronchi or lower airways. Smoke also can inhibit pulmonary macrophage function, and skin burns can worsen pulmonary status.

199

Which is a cause of primary bacterial pneumonia in dogs?

a. Pseudomonas aeruginosa

b. Mycoplasma pneumoniae

c. Pasteurella multocida

d. Bordetella bronchiseptica

d. Bordetella bronchiseptica

Although not common, Bordetella infections can develop into a primary pneumonia, particularly if the dog has a weakened immune system. Mycoplasma pneumoniae is a bacteria that can cause a primary pneumonia in humans, but it is not known to be a problem in dogs. The other choices require an underlying problem such as aspiration, foreign body, viral infection, neoplasia, etc. to be present in order to create an infection. Secondary bacterial infections can be extremely severe and need to be diagnosed and treated appropriately and aggressively.

200

What is the treatment of choice for nasal aspergillosis in dogs?

a. Surgery and antibiotics

b. Tpical antifungal therapy (i.e. Clotrimazole)

c. Systemic corticosteroids

d. Systemic antifungal therapy (i.e. Itraconazole)

b. Tpical antifungal therapy (i.e. Clotrimazole)

Topical antifungal therapy is considered more efficacious and less costly than long-term systemic antifungal therapy. Corticosteroids would be contraindicated. Surgery and antibiotics would not be successful in controlling a fungal infection. The currently recognized treatment of choice is clotrimazole, a synthetic imidazole that has an 80% cure rate with single administration. The main potential complication is CNS exposure to the drug if there has been erosion of the cribriform plate.

201

A 3 year old male Weimaraner presents to your clinic with complaints of anorexia, weight loss, and progressive exercise intolerance and dyspnea with a dry, hacking cough. On physical exam, he is cachectic (BCS 2/9), febrile (103.8 F, 39.9 C), and has diffuse peripheral lymphadenopathy. Thoracic radiographs show a diffuse nodular interstitial pattern in all lung fields. Cytology of a lymph node aspirate shows suppurative inflammation. What is the MOST likely diagnosis to explain all of these findings?

a. Lymphosarcoma

b. Kennel cough (Bordetella bronchiseptica)

c. Blastomycosis (Blastomyces dermatiditis)

d. Plague (Yersinia pestis)

c. Blastomycosis (Blastomyces dermatiditis)

These findings are most consistent with blastomycosis. Lymphoma would be a great differential but is less consistent with the nodular lung pattern and suppurative inflammation in the lymph node. Plague is an interesting differential for the lymphadenopathy and cytology findings but is not consistent with the lung pattern or history. This Weimaraner's disease is too severe to be explained by kennel cough alone. While this diagnosis is sometimes made easy by visualization of organisms in aspirates or skin scrapings, it is not always seen as in this case. Remember, Blastomyces is seen as a broad-based budding yeast. The next step to obtain a definitive diagnosis in this patient would be a transtracheal wash or bronchoalveolar lavage.

202

A 7 year old Poodle presents for a left sided head tilt, a ventral strabismus on the left, and right horizontal nystagmus. The dog is obtunded, has conscious proprioception deficits in both right limbs, and a right sided facial paralysis. Where is the lesion?

a. Central nervous system on the right

b. Peripheral nerve on the left

c. Central nervous system on the left

d. Peripheral nerve on the right

a. Central nervous system on the right

This dog has paradoxical vestibular disease. This disease is usually caused by a destructive lesion in the CNS in which there is loss of inhibition of the vestibular output on the side of the lesion. There is therefore a relative increase in vestibular output on the side of the lesion, causing vestibular signs on the side opposite the lesion (yes, this can be confusing). In this case, the right sided lesion has vestibular signs that would normally localize the lesion to the left side. When the lesion causes vestibular signs and proprioceptive deficits, the lesion is ipsilateral to the side with the proprioceptive deficits.

203

A 6 year old Cocker Spaniel with a chronic history of ear infections presents to you circling to the left, with a left head tilt, and both rotary and horizontal nystagmus with the fast phase to the right. No other neurologic deficits are apparent except for a possible hearing deficit. It is difficult to perform a thorough otoscopic examination on the patient without sedation. The dog has been on multiple topical and systemic medications to treat otitis over the past few weeks, but the owner is not sure what they are. Which of the following drugs is a commonly implicated cause of peripheral vestibular disease?

a. DImethyl sulfoxide (DMSO)

b. Enrofloxacin

c. Miconazole

d. Metronidazole

e. Chlorhexidine

f. Ticarcillin

e. Chlorhexidine

The key here is to recognize that the question is asking about peripheral vestibular disease; otherwise, metronidazole would be a good choice as a cause of central vestibular disease. Chlorhexadine is a topical drug implicated in ototoxicity and peripheral vestibular disease. Another excellent choice would be aminoglycosides including neomycin, kanamycin, tobramycin, amikacin and gentamicin.

204

A 4-year-old male castrated Beagle presented with an acute onset of being down in the hind end.

On neurological examination, the patient's cranial nerves are intact. He has bilateral hind limb conscious proprioceptive deficits and no motor function in either hind limb. There are normo-reflexive gastrocnemius reflexes and normal to hyper-reflexive patellar reflexes bilaterally. The thoracic limbs are neurologically normal. Superficial and deep pain responses are present.

A myelogram shows the lesion in the photo below. You discuss treatment options with the owner and she declines surgery. Which of the following is the most important aspect of medical management of the likely condition?

a. Strict cage rest

b. Non-steroidal anti-inflammatory drugs (NSAIDs)

c. Exercise and physical therapy

d. Muscle relaxants

e. If the owner declines surgery, euthanasia is the only humane alternative

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a. Strict cage rest

By far, the most likely diagnosis is intervertebral disc disease (IVDD) based on the history and myelogram showing a collapsed intervertebral space at T12-13 and an extradural compressive lesion originating from the same site. IVDD can be managed by surgical decompression or non-surgically. The most important aspect of non-surgical management of IVDD is STRICT cage rest, usually for a full 8 weeks.

Exercise should be avoided during the period of cage rest. Steroids, analgesics, and/or muscle relaxants may be useful additions to the management of these dogs.

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205

A 4 year old Doberman Pinscher presents for slowly progressive ataxia and paresis of all four limbs. The owners note that the ataxia is sporadic. On physical exam, the dog has hyperreflexive spinal reflexes in all four limbs, delayed conscious proprioception in all four limbs, and neck pain on ventroflexion. What is the most likely diagnosis?

a. Hansen's Type 2 fegenerative disc disease between C1C-5

b. Vertebral fracture between C1-C5

c. Canine degenerative myelopathy

d. Cervical spondylopathy

d. Cervical spondylopathy

The signalment and clinical signs are most helpful in answering this question. Doberman Pinschers, Great Danes, and Thoroughbred horses are predisposed to cervical spondylopathy, which is a cervical vertebra malformation that causes cervical myelopathy in dogs and horses. The malformation is usually stenosis or wedging of the vertebral canal, vertebral malalignment, or vertebral instability. This disease usually manifests as ataxia and paresis of all four limbs and UMN signs of all four limbs

206

You get called to a farm that is having trouble with mid-term abortion in their cows. As you are driving up to the farm you see one of the farm dogs and you notice that the dog appears to be suffering from diffuse muscle atrophy and has trouble ambulating in the hindlimbs. You immediately make an association between the dog and the abortions. What is your primary differential?

a. Toxoplasma gondii

b. Brucella bovis

c. Epizootic bovine abortion

d. Neospora caninum

e. Chlamydophila felis

d. Neospora caninum

The definitive host is the dog (or coyote or other canidae) which aquires the infection by eating infected meat, and spreads it to cows by shedding oocysts in the pasture or feed. Although clinical signs are mainly seen as abortions and abnormal calves in herbivores, dogs may suffer from neurologic and muscular abnormalities. Infection to other dogs is usually as a result of transplacental spread. IFA is usually performed to make the diagnosis.

207

You are reviewing a myelogram of a 7-year-old male neutered Border Collie with its owner. As you show the radiographs to the owner (see below), you explain that a positive contrast agent (iohexol) was injected to help visualize lesions. More specifically, where is the contrast injected during a myelogram?

a. Epidural space

b. Subarachnoid space

c. Intraventricular space

d. Subdural space

e. Intramedullary space

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b. Subarachnoid space

A myelogram is a positive-contrast radiographic study where a contrast agent such as iohexol or iopamidol is injected into the subarachnoid space where CSF accumulates.

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208

A 5 year old male castrated German Shepherd Dog presents for a right thoracic limb monoplegia after jumping out of the back of a moving pickup truck. On physical exam, you observe superficial abrasions over his body, a right sided Horner's syndrome, and dragging of his right thoracic limb. He has no conscious proprioception, motor function, or deep pain anywhere in the right thoracic limb. What should you tell the owner?

a. The dog suffered a brachial plexus avulsion and will most likely need to have the leg amputated

b. The dog has damage to the radial nerve.  Electrodiagnostic procedures should be run to determine how much nerve funcftion remains in the limb

c. Physical therapy will greatly improve the chances that the dog will regain function of the limb

d. The dog has a brachial plexus avulsion but will likely regain function in hte limb in several months

a. The dog suffered a brachial plexus avulsion and will most likely need to have the leg amputated

Dogs that are hit by cars or who jump out of moving cars often suffer brachial plexus avulsions. Complete nerve root avulsions are not treatable and usually require amputation of affected limbs. Partial avulsions carry a better prognosis but require large amounts of time and physical therapy before seeing any improvement. The lack of deep pain and motor function in the limb is a negative prognostic indicator supporting the diagnosis of a complete brachial plexus avulsion.

209

An owner just arrived from a camping trip with his dog. He is worried about his dog that seems to have undergone a change in behavior after being attacked by a wild animal. Additionally, the owner thinks that the dog's voice has actually changed. What is your top differential?

a. Canine Distemper

b. Tetanus

c. Botulism

d. Rabies

d. Rabies

If it sounds like it could be rabies, diagnose it until proven otherwise. The signs to focus on are attacked by a wild animal, a behavior change, and a voice change. This should put rabies at the top of your list. This dog is exhibiting signs of the prodromal stage of rabies. Canine distemper is a potential differential, but you will most likely see other symptoms such as respiratory and GI signs. Tetanus will manifest itself as rigidity and botulism as flaccid paralysis. Remember that any animal with an acute behavioral change or flaccid paralysis is a rabies suspect.

210

A dog presents to you after being struck in the head with a baseball bat. The dog is obtunded, but the rest of the physical exam is normal. Which of the following factors should you try to achieve in this patient to minimize intracranial pressure?

a. High PaCO2

b. Low mean arterial pressure

c. High cerebral metabolic rate

d. High PaO2

 

d. High PaO2

PaCO2, blood pressure, PaO2, cerebral metabolism, and certain drugs can affect cerebral blood volume and intracranial pressure. In head trauma patients, you want to prevent an increase in intracranial pressure by keeping cerebral blood flow relatively low without causing hypoxia. To keep cerebral blood flow in the low-normal range, the cerebral metabolic rate and PaCO2 should be kept low. Factors that would cause the cerebral metabolic rate to go up include fever, seizures, pain, etc. Mean arterial pressure should be maintained in the normal range to prevent hypotension, hypoxia, and cerebral ischemia.

211

Which of the following is not true about cranial nerve VII (facial nerve) in a dog?

a. A branch of the facial nerve innervates the lacrimal and nasal mucosa glands

b. A branch of the facial nerve is responsible for taste in the rostal 2/3 of the tongue

c. Lesion of the facial nerve can cause vestibular signs

d. Facial nerve deficits can often be seen in animals with otitis media

c. Lesion of the facial nerve can cause vestibular signs

While conditions such as otitis media can be seen concomitant to facial nerve and vestibular signs, this occurs due to effects on CN VIII (auditory-vestibular nerve), not CN VII. Otitis media often causes deficits in CN VIII and CN VII since the two nerves run adjacent to each other through the middle ear.

The major petrosal branch of the facial nerve innervates the lacrimal and nasal mucosa glands. The chorda tympani nerve, which branches off CN VII, is responsible for taste in the rostral 2/3 of the tongue.

212

A 4 year old female spayed German Shorthaired Pointer presents with the complaint of exercise intolerance and lethargy. Thoracic radiographs are taken and are shown below. What therapy is appropriate for the most likely diagnosis?

a. Enalapril

b. Pyridostigmine

c. Rimadyl

d. Inhaled fluticasone

e. Sucralfate

 

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b. Pyridostigmine

The important thing to do in this case is to both read the question carefully and view the radiograph in concert with each other. This dog has signs and findings that are most consistent with myasthenia gravis and resultant megaesophagus. Accordingly, pyridostigmine, which is an acetylcholinesterase inhibitor (anticholinesterase), is the best answer choice. If you chose sucralfate because you saw the megaesophagus and thought the dog must have esophagitis, your thinking was accurate but you ignored the dog's clinical signs of weakness. If this dog had presented for regurgitation, that would have been a more appropriate course of action. Acquired myasthenia gravis can also be treated with systemic corticosteroids to decrease immune attack of acetylcholine receptors, but inhaled fluticasone would not do the trick. Enalapril and NSAIDs are not indicated in this patient.

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213

A 5-year old male castrated Chihuahua mix presents with a 2 day history of limping in the hind limbs. The owner reports that he is usually very active and now he seems very hesitant to jump on and off of the couch. On physical exam, the patient appears to be slightly weak in the hind, reminiscent of a drunken gait. There are no conscious proprioceptive deficits. The patellar and gastrocnemius reflexes are normal. There is resistance noted when turning the neck to the left and pain elicited on deep neck palpation. Mentation is appropriate and the cranial nerves are intact. The owners have financial concerns and can only afford limited treatment and diagnostics. In light of these constraints, what is the best treatment option?

a. Immunosuppressive doses of prednisone with strict rest

b. Intravenous dexamethasone sodium phosphate at 6 hour interval for 36 hours and strict rest

c. Non-steroidal anti-inflammatory therapy and strict rest

d. Tramadol and acepromazine with strict rest

 

c. Non-steroidal anti-inflammatory therapy and strict rest

The most recent literature shows that 50% of dogs with clinical signs of intervertebral disc disease will improve with medical management alone. Medical management involves restricted activity and anti-inflammatory therapy. Prednisone, methyl-prednisolone sodium succinate, and non-steroidal anti-inflammatories are commonly used. Prednisone, if used, should be prescribed at an anti-inflammatory dose and not immunosuppressive. Dexamethasone sodium phosphate has only been shown to increase the likelihood of side effects and complications such as urinary tract infection and is therefore not recommended.

214

A 7-year old male castrated Doberman presented for lethargy, anorexia, and a left forelimb lameness. He was started on meloxicam two days ago for neck pain and improved significantly, but he became very lethargic and inappetent last night and had a tarry stool. On physical exam, he had full range of motion in his neck, a hunched stance, conscious proprioceptive deficits in all feet, and his left forelimb was held in an abducted stance. He had a short choppy gait in his thoracic limbs and long lanky gait in his hind limbs. Hematochezia was noted on rectal palpation. Brief ultrasound did not show any evidence of pleural, pericardial, or abdominal effusion. The owners do not wish to pursue any diagnostics. What is your recommended treatment plan for the neurologic disease process you suspect?

a. Recommend euthanasia; it is likely a tumor

b. Discontinue meloxicam.  Start an oral opioid-based pain medication for 5 days.  Then start an anti-inflammatory dose of a steroid.

b. Add an opioid pain medication (such as Tramadol) and recommend strict cage rest for 14 days

d. Switch him from meloxicam to prednisone and recommend strict cage rest

b. Discontinue meloxicam.  Start an oral opioid-based pain medication for 5 days.  Then start an anti-inflammatory dose of a steroid.

This dog has the classic two-engine gait characteristic of Wobbler's syndrome. The hematochezia noted on rectal exam, and the history of a tarry stool (suggesting upper GI bleeding) is likely due to the meloxicam which should be discontinued immediately. Medical management for Wobbler's syndrome involves an anti-inflammatory dose of a steroid. There is a three to five day wash out period needed after stopping meloxicam and before starting prednisone.

Further diagnostics for Wobbler's syndrome involves imaging (cervical radiographs, myelogram, MRI or CT) and it can be helpful in ruling out neoplasia or traumatic injuries. The left forelimb lameness and abducted stance are likely due to a pinched nerve however further imaging would be needed for confirmation.

 

215

Based on the direction of this dog's head tilt, where would you localize the lesion to if he has a paradoxical vestibular syndrome?

a. Right cranial nerve VIII (vestibulocochlear nerve)

b. Right cerebellum

c. Left cerebellum

d. Left cerebral hemisphere

e. Left cranial nerve VIII (vestibulocochlear nerve)

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b. Right cerebellum

This dog has a left head tilt by definition because his left ear is closer to the ground. The key to answering this question is seeing the left head tilt and reading that the question asks about PARADOXICAL vestibular disease.

Vestibular disease can be peripheral or central, and central vestibular disease can be classic in appearance or paradoxical. Peripheral vestibular disease is due to a lesion in the inner ear or vestibular portion of cranial nerve VIII. Classic central vestibular disease is due to a lesion in the brainstem or cerebellum. Signs with peripheral and classic central vestibular disease include head tilt, falling, and circling to the same side as the lesion with nystagmus with fast phase to the opposite side.

With paradoxical vestibular disease, the lesion is in certain regions of the cerebellum (flocculonodular lobe) or caudal cerebellar peduncle and produces signs to the opposite sides from which is seen with peripheral and classic central disease.

216

A 9-year old male Queensland Heeler presents with a four day history of progressive tetraparesis. Physical exam showed him to be weakly ambulatory with support. As part of your initial workup, you take chest X-rays which are shown below. Which of the following next steps is the most appropriate test to confirm your clinical suspicion about the cause of the dog's signs?

a. CT scan of the thorax

b. Tensilon response test

c. MRI of the brain

d. Myelogram

e. Bronchoalveolar lavage and culture

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b. Tensilon response test

The correct answer is a Tensilon (edrophonium) response test. Hopefully, you were able to identify the mass in the cranial mediastinum on the chest radiograph, as this was one of the keys to this case. This, in conjunction with the dog's other signs, are suggestive that this dog has a thymoma and associated secondary myasthenia gravis. Tensilon (edrophonium) is a rapidly acting anticholinesterase that reverses signs of myasthenia within minutes in most dogs.

A chest CT would be a valid test to confirm the presence of the mediastinal mass and might be an appropriate test before surgery but would not bring you closer to a diagnosis if you already have identified the mass. An MRI of the brain would assess a CNS cause of the dog's signs, which are unlikely, given the other findings. Similarly, a myelogram would assess if a spinal cord lesion caused the dog's signs, but the rest of the findings in this case should point you in a different direction.

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217

A 10 year old female spayed Labrador Retriever has presented for difficulty getting up in the hind and apparent back pain for the last 3-4 weeks. Upon questioning the owner, you are told that her appetite is diminished but she is still eating. An orthopedic exam finds no pain or discomfort elicited on manipulation of the hips or stifles. A neurologic exam identifies substantial pain in the lumbosacral region; however, conscious proprioception is intact, and patellar reflexes are normal.

Radiographs of the lumbosacral region identify a lytic lesion at the L7-S1 endplates as well as surrounding bony proliferation. Which of the following diagnostic tests is likely to provide the most helpful additional information given your findings?

a. Urine culture

b. Blood draw for creatine kinase levels

c. Abdominal ultrasound

d. Chest radiographs

e. Stifle arthrocentesis

a. Urine culture

The diagnosis you should have in mind is discospondylitis. Be sure not to confuse this with spondylosis, which is typically not clinically significant and can be expected in most older dogs. The radiographic description is relatively specific for this condition. Neoplasia in the spine should be lower on your differential list because it typically does not cross joints. Disc herniation cannot be ruled out, and advanced imaging would be necessary to know for certain, but given the exam and radiographic findings, discospondylitis should be your top differential.

Discospondylitis is usually bacterial in origin, with Staphylococcus being the most common organism involved. Other organisms identified include Brucella canis, E. coli, Pasteurella, Aspergillus, and Streptococcus.

In an attempt to identify the causative agent, urine and blood cultures should be considered. The other answer choices are not as high yield in identifying the specific bacterial cause or underlying etiology.

218

Which of the following is the most likely side effect of KBr therapy in epileptic dogs?

a. Vomiting

b. Pancreatitis

c. Polyuria and polydipsia

d. Sedation

 

d. Sedation

Possible side effects of KBr therapy include polyphagia, polyuria and polydipsia, ataxia, skin reactions, pancreatitis, and vomiting. However, sedation is more likely to occur than these.

219

Dilated cardiomyopathy is a common disease seen in dogs. Which one of the following medications is indicated for the treatment of DCM?

a. Adriamycin

b. Atropine

c. Enalapril

d. Prednisone

 

c. Enalapril

The correct answer is enalapril. All others would be contraindicated. Enalapril is an ACE-inhibitor, which blunts the adverse effects of the renin-agiotensin-aldosterone system thereby reducing sodium and fluid retention. Additionally, ACE-inhibitors cause mild vasodilation by preventing the production of angiotensin-II, which reduces ventricular afterload. Lastly, enalapril and other ACE-inhibitors are protective to cardiac muscle by blunting aldosterone and other hormones which induce cardiac remodeling.

220

A 1.5-year old male castrated Boxer presents for exercise intolerance and syncopal episodes. Cardiac auscultation reveals a grade 4/6 left systolic murmur heard best at the base of the heart. Thoracic radiographs show a mildly enlarged left ventricle and left atrium, and segmental enlargement of the ascending aorta. What test will best help you to confirm your tentative diagnosis?

a. Echocardiogram

b. Heartworm antigen test

c. 24 hou Holter ECG monitor

d. Coombs' test

e. CT scan

a. Echocardiogram

The breed, clinical history of syncope, radiographic findings, and auscultation findings are most consistent with aortic stenosis. Echocardiography would be the best method for diagnosing the disease in which you would find left ventricular concentric hypertrophy, stenosis of the aortic outflow tract, and post-stenotic dilatation of the ascending aorta.

A Holter monitor is the test of choice for arrhythmogenic right ventricular cardiomyopathy (ARVC) which is also seen in Boxers and causes syncope but does not fit with the physical exam or radiographic findings. Also called Boxer cardiomyopathy, ARVC is a disease associated with fibrofatty infiltrate into the right ventricle resulting in electrical conduction disturbances and resultant VPCs.

A CT scan would not add more information, and cardiac motion typically causes resolution problems on thoracic CT scans. The signs are not consistent with heartworm, which is primarily a right heart problem, or with hemolytic anemia, which a Coombs' test might be useful for.

221

Which of the following findings is not consistent with Tetralogy of Fallot in a dog?

a. Pulmonary hypoperfusion

b. History of failure to thrive

c. Polycythemia

d. Severe generalized cardiomegaly on thoracic radiography

e. History of exercise intolerance

d. Severe generalized cardiomegaly on thoracic radiography

Tetralogy of Fallot is a congenital defect of the heart which includes pulmonic stenosis, dextro-positioned aorta (over-riding), right ventricular hypertrophy, and a ventricular septal defect. It causes shunting of venous blood across the VSD into the arterial circulation which leads to hypoxemia, and an increased drive for erythropoiesis causing polycythemia. Affected animals tend be underdeveloped in size and have a history of exercise intolerance, dyspnea, tachypnea, or syncope due to hypoxemia. Thoracic radiographs usually show a normal to mildly enlarged cardiac silhouette with right ventricular enlargement and pulmonary hypoperfusion due to the shunting of venous blood into the arterial circulation.

222

A 9 month old shepherd cross presents for lethargy and exercise intolerance. Your physical exam reveals dark red mucous membranes and a heart murmur. A CBC reveals a hematocrit of 70% (35-57%). Which of the following could NOT explain the given findings?

a. Atrial septal defect with systemic hypertension

b. PDA with pulmonary hypertension

c. Atrial septal defect with tricuspid stenosis

d. Tetralogy of Fallot

a. Atrial septal defect with systemic hypertension

This dog's polycythemia developed due to shunting of venous blood into the arterial circulation (aka right-to-left shunting) leading to hypoxemia and an increased drive for erythropoiesis and secondary polycythemia. This can be caused by any of the other 3 answer choices. An atrial septal defect with systemic hypertension results in oxygenated blood shunting into the venous circulation or left-to-right shunting, which usually does not cause hypoxemia.

223

Which of the following clinical findings is not consistent with a left-to-right shunting patent ductus arteriosus?

a. Continuous heart murmur

b. Bounding arterial pulses

c. Aneurysmal bulge of the aorta on thoracic radiographs

d. Increased QRS amplitudes on electrocardiography

e. Right ventricular enlargement

e. Right ventricular enlargement

Right ventricular enlargement is consistent with a right to left shunting PDA. A continuous, or "machinery" murmur is characteristic of a PDA. Bounding or "waterhammer" arterial pulses are common due to the increased systolic pressure and decreased diastolic blood pressure (widened pulse pressure). An aneurysmal bulge is often seen on the dorso-ventral view of thoracic radiographs. Left chamber enlargement occurs with left-to-right shunting PDAs which can often be detected as increased amplitude of the QRS complex on ECG.

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A 7-year old female spayed Doberman Pinscher presents for lethargy and anorexia. Your physical exam reveals a 3/6 left systolic heart murmur and a rectal temperature of 103.5F (39.7 C). Echocardiography shows a vegetative lesion on a mitral valve leaflet. If conventional blood cultures are negative, which of the following organisms should be considered?

a. Bartonella sp.

b. Aspergillus sp.

c. Salmonella sp.

d. Mycoplasma sp.

a. Bartonella sp.

The most commonly reported organisms recovered in animals with endocarditis include Staphylococcus aureus, Streptococcus sp., Corynebacterium sp., Pseudomonas aeruginosa, Erysipelothrix, E. coli, and Bartonella sp.

225

Taurine deficiency in the English Cocker Spaniel has been associated with which of the following?

a. Dilated cardiomyopathy

b. Retinal detachment

c. Superficial pyoderma

d. Hypertrophic cardiopathy

a. Dilated cardiomyopathy

Although taurine deficiency is rare nowadays, it has been associated with DCM in cats and some dogs (English Cocker Spaniels). Commercial cat and dog foods now contain acceptable levels of taurine. In cats, retinal dysplasia also occurs with taurine deficiency.

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A 12-year old female Dalmatian has a Holter monitor placed for an arrhythmia heard on exam. The following trace is from that monitor; similar abnormalities were seen frequently throughout the 24hrs. What is your treatment recommendation for this arrhythmia?

a. Pimobendan

b. Amlodipine

c. Mexiletine

d. Diltiazem and furosemide

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c. Mexiletine

The Holter ECG shows a couplet of ventricular premature complexes. If frequent ventricular ectopy is seen, particularly with runs or R-on-T episodes, treatment is advised with oral ventricular antiarrhythmics. Mexiletine is an oral class I antiarrhythmic that is well-tolerated in dogs. Pimobendan improves systolic function, but does not treat arrhythmias. Amlodipine is a calcium channel blocker used for patients with systemic hypertension. Diltiazem is used for supraventricular tachycardias to slow conduction down the AV node. Furosemide is a diuretic used in the treatment of heart failure, it does not have antiarrhythmic properties.

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A 10 year old male intact Labrador Retriever presents to your clinic for a two week history of lethargy, decreased appetite, and one episode of vomiting. You auscult a very regular bradycardia, perform an ECG and obtain the following. All of the following are true concerning this arrhythmia except_______________.

a. A permanent pacemaker is almost always indicated in patients with this rhythm

b. Intravenous lidocaine administration is always contraindicated with this arrhythmia

c. This arrhythmia is often secondary to hyperkalemia

d. Although atropine is indicated with the bradyarrhythmia, it will rarely increase the ventricular rate

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c. This arrhythmia is often secondary to hyperkalemia

The rhythm diagnosis is third degree (complete) AV block. Atropine is often administered in attempts to increase the ventricular rate in these patients but almost never significantly increases the heart rate. The cause of complete AV block is normally unknown, but is rarely improved with medical management or time, thus typically necessitating an artificial pacemaker. Intravenous lidocaine is ABSOLUTELY contraindicated in these patients since this may abolish the ventricular escape rhythm. Though atrial standstill may be secondary to hyperkalemia, this rhythm is clearly not an atrial standstill since there are P-waves evident (hence atrial depolarization).

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An 11-year old female Pomeranian presents to you for coughing and exercise intolerance. On exam: Wt: 9.25 lbs, T: 101.2F (38.4 C), HR: 132 bpm, RR: Panting, mucous membranes are pink. She has mild tracheal sensitivity and a grade III-IV/VI left apical holosystolic murmur and grade II/VI right apical holosystolic murmur. Femoral pulses are strong and synchronous, with a regular rhythm. She has harsh lung sounds bilaterally. On abdominal palpation, you note hepatomegaly. You find bilateral luxating patellas.

You take chest radiographs (see image) and decide to treat the dog based on these findings. Which medication plan is most appropriate?

a. Furosemide and enalapril

b. Atropine and temporary pacemaker

c. Immiticide (Melarsomine)

d. Clavamox and enrofloxacin

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a. Furosemide and enalapril

The radiograph here shows a severe symmetrical alveolar pattern in the perihilar region extending to the right and left caudal lung lobes. The heart is tall on the lateral view causing dorsal elevation of the trachea.

This, in conjunction with the physical findings, is compatible with left congestive heart failure (CHF) secondary to mitral valve regurgitation. The dog also has hepatic congestion evident by enlargement on the radiograph. Treatment for CHF include diuretics (furosemide/Lasix, hydrochlorothiazide, spironolactone), arterial vasodilators (enalapril, benazepril, amlodipine, hydralazine), positive inotropes (pimobendan), and venodilators (nitroglycerine).

Clavamox and enrofloxacin are antibiotics which could be used to treat pneumonia, but that is not this dog's problem. Immiticide is the treatment for heartworm. Atenolol is a beta blocker and not part of the management of mitral regurgitation or CHF. Atropine or a pacemaker would be indicated for conduction problems.

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Which of the following is not a result of pulmonic stenosis in a dog?

a. Increased right ventricular systolic pressure

b. Dilation of the main pulmonary artery immediately downstream of the stenotic region

c. Concentric hypertrophy of the right ventricle

d. Increased right atrial pressure

e. Left ventricular hypertrophy

e. Left ventricular hypertrophy

The left heart is not affected by pulmonic stenosis. Concentric hypertrophy occurs in the right ventricle as a result of the increase in pressure in the right heart caused by the increase in resistance to the ejection of blood through a stenotic pulmonary outflow tract. The post-stenotic dilation develops as a result of turbulent blood flow.

230

A 6-month old male German Shepherd Dog presents for castration. A 4/6 left systolic murmur is heard best over the apex of the heart. Thoracic radiographs reveal a moderately enlarged left atrium. What is the most likely diagnosis?

a. Mitral valve dysplasia

b. Myxomatous degeneration of the mitral valve

c. Aortic stenosis

d. Tricuspid valve dysplasia

a. Mitral valve dysplasia

This abnormality is a congenital anomaly of the mitral valve. The valve leaflets may be thickened, fused, fibrosed, etc. The chordae tendinae or the papillary muscles attaching to the mitral valve may be irregular as well. German Shepherd Dogs, Great Danes, and other large breed dogs are predisposed to this disease. Myxomatous mitral valve degeneration occurs in older dogs, but would otherwise result in similar physical exam and radiographic findings as those described. Tricuspid dysplasia results in an enlarged right heart, and the murmur would be heard best on the right side of the dog. Aortic stenosis results in concentric hypertrophy of the left heart, which may or may not be detectable on radiographs. Also, the murmur is heard best at the left heart base with aortic stenosis.

231

A 9 year old male castrated English Setter presents for lethargy, anorexia, and tachypnea. Your physical exam reveals markedly muffled heart sounds. Which of the following is most supportive of a diagnosis of pericardial effusion in this dog?

a. Waterhammer pulses

b. Weak pulses and hepatomegaly

c. 3rd degree AV block

d. Electrical alternans and pulsus paradoxus

e. Thoracic radiographs where the interface of the heart and lung parenchyma is abscured

 

d. Electrical alternans and pulsus paradoxus

Electrical alternans is an ECG finding in which the height of QRS complexes alternate due to the physical swinging of the heart as it contracts within the pericardial effusion. Pulsus paradoxus is an exaggerated decrease in arterial pulse quality during inspiration caused by increased right-sided filling at the expense of reduced left ventricular filling because the heart is constrained by the pericardial effusion. Third degree AV block does not occur with pericardial effusion. Obscuring of the cardiac/pulmonary parenchyma interface is usually due to pulmonary parenchyma changes or pleural effusion. Weak pulses and hepatomegaly are not specific to pericardial effusion, though are often present in dogs with severe pericardial effusion. Waterhammer pulses are palpated with PDAs or severe aortic regurgitation.

232

A 7 month old male Labrador Retriever presents for lethargy, a distended abdomen, and exercise intolerance. Your physical exam reveals a 4/6 systolic murmur heard best at the right mid thorax. Thoracic radiographs show severe cardiomegaly with marked right atrial enlargement and right ventricular enlargement. The caudal vena cava is enlarged, and part of the abdomen in the film shows loss of serosal detail and hepatomegaly. What is your most likely diagnosis?

a. Hepatocellular carcinoma

b. Hemangiosarcoma

c. Pulmonic stenosis

d. Tricuspid dysplasia

d. Tricuspid dysplasia

Tricuspid dysplasia is similar to mitral valve dysplasia in the irregular valve leaflets, chordae tendinae, or papillary muscles of the valve. Labrador Retrievers, German Shepherd Dogs, and other large breed males are predisposed to the disease. Signs of right heart failure, such as ascites and hepatomegaly occur in advanced disease. The prognosis for these animals is guarded to poor depending on the severity of the regurgitation. Pulmonic stenosis causes a pressure overload of the right heart and causes concentric hypertrophy, which may or may not be detectable by radiography. The murmur with PS is heard better at the left heart base. Hemangiosarcoma and hepatocellular carcinoma are less likely in a 7 month old puppy.

233

This ECG recording (bottom recording) is from a 10-year old miniature poodle with a history of heart disease that is untreated. She presented for a 3-day history of diarrhea and decreased appetite. On physical examination you auscult a grade III/VI heart murmur and clear lung sounds. There are no obvious pulse deficits palpated. What is the appropriate treatment for this arrhythmia?

a. No anti-arrhythmic therapy is necessary at this time

b. Begin the patient on oral mexiletine and recheck an ECG strip in 5 days

c. Give the patient a bolus of lidocaine and begin continuous infusion for twelve hours and then try to wean off the lidocaine

d. Give the paitnet an intravenous injection of furosemide and begin oral administration of furosemide

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a. No anti-arrhythmic therapy is necessary at this time

There are several general guidelines/recommendations regarding treatment of ventricular premature contractions which is what is shown on the ECG strip. These include a heart rate of over 180 bpm, pulse deficits, clinical signs, and VPCs for over 20 seconds in duration. In this case, the heart rate is visible on the recording and clearly not elevated. The patient's physical exam findings are not suggestive of an immediate problem secondary to the arrhythmia. There are many dogs with intermittent VPCs that are not of clinical importance. However, it is recommended that the patient be evaluated regularly and ideally have a consultation with a cardiologist to ensure the progression of heart disease is being minimized.

Furosemide is not indicated as there is not an indication that the patient is fluid overloaded or in fulminant heart failure.

Mexiletine is a Class IB anti-arrhythmic and is not necessary given the lack of severity in the ECG findings.

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A 9 year old female spayed black Labrador Retriever presents to your clinic with the complaint of collapse and lethargy. On exam, the dog is subdued but responsive with a temperature of 100.9F (38.3 C), heart rate of 170 beats per minute, and respiratory rate of 40 breaths per minute. You perform chest radiographs which are shown below. A CBC shows a hematocrit of 31% (35-57%), neutrophil count of 6,275/ul (2,900-12,000/ul), monocyte count of 984/ul (100-1,400/ul) and eosinophil count of 630/ul (0-1,300/ul). What is the treatment of choice?

a. Terbutaline

b. Broad spectrum antibiotics

c. Furosemide

d. Pericardiocentesis

e. Melarsomine

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d. Pericardiocentesis

This radiograph and case are a good example of pericardial effusion with the classic finding of a markedly enlarged heart with a globoid shape. The most common type of effusion by far is hemorrhage which can be idiopathic or from neoplasia such as hemangiosarcoma. Based on this finding, in conjunction with the dog's tachycardia, a pericardial tap for both diagnostic and therapeutic purposes is indicated. Furosemide is contraindicated in cases of pericardial effusion because it will decrease preload in the right side of the heart and can promote circulatory failure. Melarsomine is the treatment for heartworm. Antibiotics are very unlikely to help this dog unless the effusion is from some sort of infectious pericarditis, which would be extremely unusual in dogs.

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235

A 4-year old female spayed mixed Chihuahua presented to the emergency service at approximately 5am this morning after presumptively being attacked by a coyote. The patient has a flail chest and it is questionable if there is direct communication between the thoracic cavity and the environment (it was difficult to examine the dog due to her fractious nature). Exploration of the wound was performed, and once anesthetized, it was apparent she had a pneumothorax. The patient must be ventilated, as there is no vacuum present in the chest for lung expansion to occur. What pressure should the anesthetist not exceed if manually bagging the patient during anesthesia?

a. 24cm H2O

b. 12cm H2O

c. 20cm H2O

d. 8cm H2O

c. 20cm H2O

Pressures above 20cm H20 may result in barotrauma. In an otherwise healthy patient it is not recommended to exceed this pressure. In patients with chronic atelectasis, anesthetists will be much more apprehensive about over ventilating or ventilating the lungs too quickly, as acute expansion can trigger re-expansion pulmonary edema, which may then lead to acute respiratory distress syndrome and death.

236

Which of these inhalant anesthetics has the fastest onset of action in the dog?

a. Diethyl ether

b. Isoflurane

c. Desflurane

d. Halothane

c. Desflurane

Speed of action of inhalant anesthetics is most directly related to blood-gas solubility. Desflurane has the lowest solubility and therefore, has the fastest time of action. In order from fastest to slowest, the inhalants are (desflurane, NO, sevoflurane, isoflurane, enflurane, halothane, diethyl ether, methoxyflurane).

237

A 10 year old male castrated Shetland Sheepdog presents to you with progressive neurologic signs including ataxia and seizures. Bloodwork and serum chemistry values are within normal limits. You are preparing to anesthetize the dog for imaging of the brain to determine if there is an intracranial mass. The Cushing's reflex describes what response to increased intracranial pressure in a dog?

a. Tachycardia and hypertension

b. Tachycardia and hypotension

c. Bradycardia and hypotension

d. Bradycardia and hypertension

 

d. Bradycardia and hypertension

In order to perfuse the brain when there is increased ICP, the body needs to increase systemic blood pressure to overcome that pressure. This occurs primarily through reflex vasoconstriction. The increase in blood pressure leads to decreased heart rate. Therefore, Cushing's reflex is when increased ICP leads to hypertension and bradycardia.

 

238

One of your colleagues has asked you to be the anesthetist for a lung lobectomy in an 8 year old Pug with a lung lobe torsion. He stresses that there will be times in the procedure where it is absolutely critical that the dog stay completely still, including no respiratory motion. Which of the following drugs could be used to do this while maintaining the dog under a reasonable surgical plane of anesthesia?

a. Isoflurane gas and injectable succinylcholine

b. Isoflurane gas and a lidocaine infusion

c. Sevoflurane gas and a fentanyl infusion

d. Sevoflurane gas and injectable edrophonium

e. Propofol constant rate infusion

a. Isoflurane gas and injectable succinylcholine

To control all respiratory motion without pushing a dog to an excessive and dangerous plane of anesthesia, a neuromuscular blocking agent would be necessary. You would never use one of these alone for a surgical procedure as they do not provide analgesia or reduce consciousness, which is why an inhalant gas anesthetic is also used to maintain anesthesia in this case.

Options include succinylcholine which is a depolarizing neuromuscular blocker or one of the nondepolarizing neuromuscular blocking agents such as pancuronium, d-tubocurarine, and atracurium.

Edrophonium is a cholinesterase inhibitor which can be used to reverse neuromuscular blockers. Fentanyl is an opioid and is actually an excellent choice to provide pain control and decrease the concentration of gas anesthetic needed in a procedure such as this one, but it would not accomplish the goal of preventing all motion, including respiration when necessary.

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