Equine Flashcards
(124 cards)
1
Q
What is entropion?
A
common condition in foals where the lower eyelid is inverted and can cause conjunctivitis or keratitis. The condition will usually correct spontaneously but sometimes will require treatment to evert the lid. One method for this is to use a local anesthetic, mechanically evert the lid, and staple it. Alternatively, surgical correction can be performed but is rarely indicated.
2
Q
what is Ectropion?
A
where the eyelid everts out and can lead to exposure keratitis, but this is uncommon in horses.
3
Q
All aminoglycosides have the potential for causing tubular nephrosis. Which aminoglycoside is most nephrotoxic to horses?
A
Neomycin.
4
Q
On physical exam, you are able to extend the hock and flex the stifle simultaneously. What is your diagnosis?
A
peroneus tertius rupture. Damage to the peroneus tertius muscle disrupts the stay apparatus of the hind limb.
5
Q
most consistent with a diagnosis of chronic obstructive pulmonary disease in the horse?
A
end expiratory wheezes. As lung volume decreases during expiration, the narrowed bronchioles collapse shut (dynamic airway collapse). This traps air distal to the closure and creates the wheezes heard as the airways narrow towards the end of expiration.
6
Q
By what mechanism does Parascaris equorum typically cause colic in foals?
A
Intestinal impaction
7
Q
Consumption of an ionophore in a horse classically results in ________.
A
myocardial toxicity. The main ionophore that results in toxicity is monensin. Horses are very susceptible to monensin toxicity.
8
Q
What is the definitive host of Dictyocaulus arnfeldi?
A
The correct answer is donkey. Dictyocaulus is the lungworm of horses. Horses housed with donkeys are at highest risk for acquiring the disease. In donkeys and in foals, Dictyocaulus is usually subclinical. The life cycle of the worm is that an infective larva is ingested and migrates through the mesenteric lymph nodes through lymphatics to the lung, where it develops into an adult and produces eggs that are coughed up, swallowed, and passed in the feces.
9
Q
24 year old Peruvian Paso, a harsh and decrescendo holodiastolic 3/6 murmur is auscultated with a point of maximum intensity at the left base of the heart. What is the most likely diagnosis
A
This horse most likely has aortic regurgitation due to degeneration of the aortic valve and should have no impact on performance
10
Q
typical presentation and findings of a horse with bog spavin which refers to swelling of the tibiotarsal joints. What is tx?
A
Although this has the potential to be associated with lameness and or poor conformation, there is often no other clinical abnormality detected. No treatment is generally needed
11
Q
A 20-year old mare is presented for a dermal nodule on her head. An aspirate of the mass reveals that it is a mast cell tumor. What is the prognosis for this horse?
A
The correct answer is good; the tumors are benign and excision is usually curative. Mast cell tumors in horses are benign. They can occur anywhere on the horse, but are often found in the dermis or subcutis of the head or legs.
12
Q
What is the most common way in which equine herpesvirus is transmitted?
A
Inhalation
13
Q
how long should it take for the placenta to be expelled after parturition ?
A
30min to 3hrs. it is considerate retained after 3-6hrs
14
Q
what is Theiler’s disease
A
(aka serum sickness or serum hepatitis). Theiler’s disease will cause and acute multifocal to diffuse hepatitis along with necrosis too.
15
Q
What is the proper site for thoracocentesis for pleural effusion removal in the horse if ultrasound is not available?
A
7th rib space at costochondral junction
16
Q
what is the Coggins test?? if a horse if positive for it, can we still give it corticosteroids ?
A
Coggins test checks for Equine Infectious Anemia (EIA) antibodies in the horse’s blood. NO because it tends to cause recrudescence of viremia and worsen anemia
17
Q
what is Culicoides hypersensitivity?
A
also referred to as sweet itch, occurs due to allergy to the saliva of the gnat. It recurs seasonally in the warmer months and tends to worsen with age. Typically, horses are pruritic and develop lesions on the poll, mane, and tail from self trauma.
18
Q
what is Habronemiasis?
A
Habronemiasis is a condition where the larvae of the stomach worm migrate and emerge creating granulomatous lesions, usually around the eye, male genitalia, or lower extremities. Inside the granulomas, you can find dead larvae.
19
Q
what is Haematobia
A
Haematobia irritans is a bigger problem in cattle than horses (they reproduce in cow feces) but can affect horses, especially ones that are near cattle. It typically causes ventral midline dermatitis with wheals with a central crust that progress to alopecia and ulceration with fairly focal lesions, rather than more diffuse lesions caused by Culicoides.
20
Q
what is Onchocerca?
A
Onchocerciasis, also known as river blindness, is a disease caused by infection with the parasitic worm Onchocerca volvulus. can cause dermatitis in the horse due to hypersensitivity to dying microfilariae. Lesions include alopecia and scaling of the ventral midline, face, and pectoral region. Often, lesions are diamond shaped and there may be a “bull’s eye” lesion on top of the head. Onchocerciasis in horses causes a ventral midline dermatitis that is non-seasonal and mildly pruritic or not pruritic at all.
21
Q
Which of the following can be used as treatment of mild, acute laminitis.? 1) Prednisone 2)Trimethoprim sulfa 3)Application of horse shoes 4)Phenoxybenzamine
A
Phenoxybenzamine is an alpha-adrenergic antagonist promoting vasodilation and restoration of blood flow to the digits. Prednisone is contraindicated in laminitis because corticosteroids are believed to induce the condition.
22
Q
______ foals that are homozygous for the SCID gene appear normal at birth but then develop fatal infections, often from unusual organisms like Pneumocystis. The SCID trait is autosomal recessive. A genetic test now exists for this disease.
A
Arabian
23
Q
what is Guttural pouch tympany
A
condition where the pouch becomes distended with air. It is thought to be due to a defect in the Eustachian tube or pharyngeal tissues. It leads to a characteristic non-painful, air-filled swelling and is treated by fenestrating the membrane between the normal and affected pouch.
24
Q
what is the tx for equine cushing’s?
A
Pergolide -dopamine agonist to help decrease symptoms
25
what is the most common ovarian tumor in horses that can lead to aggression ?
granulosa cell tumor
26
buccal mucosal bleeding test is equivalent to ___ \_\_\_\_ \_\_\_\_\_
template bleeding time. It can determine functional ability of platelets to plug a minute wound
27
most common gastril neoplasia in the horse vs the dog
-horse is SCC -dog is adnocarcinoma
28
Strongyloides westeri is the \_\_\_\_\_. How do foals get them and what is the tx?
equine thread worm. Common in foals because it is transmitted in the mare's milk. tx is ivermectin or oxibendazole
29
Total body water is \_\_\_% of body weight. Extracellular fluid is approximately \_\_\_/\_\_ of total body water
60% and 1/3
30
What is the normal blood lactate in a healthy foal or horse?
2.5mmol/l
31
dental formula for horses
2(I3/3 C1/1 P3-4/3 M3/3)
32
How much sodium bicarbonate must be given to a 470kg horse that has a base deficit of 13 to completely correct this deficit?
0.4 x BW x Base Deficit
33
Common clinical signs associated with fescue toxicosis in pregnant mares?
Common clinical signs associated with fescue toxicosis include prolonged gestation and/or decreased milk production (agalactia). Ergopeptine alkaloids are ingested by the mare, which act as dopamine agonists. Dopamine serves to inhibit prolactin, thus inhibiting lactation. Placental thickening and weak or stillborn foals may also occur.
34
1-Yellow star thistle (Centaurea solstitialis)
2-Oak leaves and acorns (Quercus sp)
3-Red maple leaves (Acer rubrum)
4-Black walnut (Juglans nigra)
1-Yellow star thistle causes nigropallidal encephalomalacia resulting in CNS signs.
2-Causes diarrhea and abdominal pain
3-Hemolysis and low oxygen content of the blood
4-Black walnut is associated with laminitis.
35
What is the most common cause of blindness and cataract in horses?
Equine recurrent uveitis
36
Which of these tests would be the best indicator of moldy sweet clover toxicity in a horse?
The correct answer is prothrombin time (PT). Sweet clover can contain a number of fungi that create dicumarol, a warfarin-like toxin. It inhibits vitamin K and interferes with synthesis of factors II, VII, IX, and X. Because factor VII has the shortest half-life of these factors, it will be depleted first. Factor VII is involved in the extrinsic coagulation pathway and would therefore, be elevated first after ingestion of sweet clover. PT is a measure of the extrinsic pathway (and common).
37
tx for a horse with "stringhalt"
lateral digital extensor tenectomy
38
Bog Spavin vs Bone Spavin
Bone spavin: osteoarthritis of the distal intertarsal joint and/or tarsometatarsal joint
Bog spavin: synovial distention of the tarsocrural joint, does not cause lamness
39
What is "ringbone" in horses and how do you treat it ?
Ringbone is osteoarthritis of the phalanges. It can be caused by poor conformation, improper shoeing, and trauma such as wire cuts or repetitive concussion on hard surfaces. Diagnosis can be made on palpation of soft tissue thickness and new bone formation in the pastern region as well as by radiography. Range of motion of the involved joints is decreased and regional nerve blocks can help localize the problem area. Complete rest is the most important requirement for treatment. Cold packing, astringent applications, and radiation therapy can be useful early on in the disease, and anti-inflammatories can help relieve pain. Surgical arthrodesis of the pastern joint is curative and can restore a young horse back to performance status.
40
African Horse Fever
- transmission
- Clinical Signs
- transmission: Culicoides (little fly) and mosquitoes
- sings: begin with fever and conjunctivitis. Some animals may recover but many go on to develop the pulmonary and/or cardiac forms. (Pulmonary = acute respiratory distress, coughing, sweating, and foaming from the nostrils;usually fatal). (Cardiac =edema of the head/neck + abdominal pain and depression; 50% diein about 1 week)
41
The classic findings of renal failure include: \_\_\_\_\_\_, \_\_\_\_\_\_\_, \_\_\_\_\_\_\_, \_\_\_\_\_\_\_
The classic findings of renal failure include hyponatremia, hypochloremia, hyperkalemia, and azotemia. Somewhat unique to the horse, hypercalcemia is noted because of the high amounts of calcium present in the diet. Serum phosphorus levels may be low because of the high calcium.
42
what is the classical sign of ionophore toxicity in the horse
myocardial toxicity; usually happens when cow feeds gets mixed up with horse feed and horse eats monensin
43
Chorioptic mange is caused by infestation with Chorioptes \_\_\_\_; where does the mite usually live?
Chorioptic mange is caused by infestation with Chorioptes equi; this mite typically affects the distal limb region but can also extend to the ventral abdomen. Draft horses are particularly susceptible because of their long feathered hair coat of the distal limbs. Chorioptes is more common in the winter months and causes intense pruritus.
44
Arabian foal with persistent infection should be suspected of having this heritable immunodeficiency of ___ and ____ \_\_\_\_\_\_\_. Typically, foals with CID do not demonstrate evidence of repeated infection until maternal antibodies begin to wane. There is no treatment for this disease.
Arabian foal with persistent infection should be suspected of having this heritable immunodeficiency of B and T lymphocytes. Typically, foals with CID do not demonstrate evidence of repeated infection until maternal antibodies begin to wane. There is no treatment for this disease.
45
What is the most common cause of colic in a newborn foal?
Meconium impaction occurs in the rectum or small colon. Clinical signs include straining, swishing of the tail, and restlessness. Rectal examination reveals numerous hard fecal balls. Treatment consists of an enema with water and a mild soap. Meconium is the first intestinal discharges of the newborn foal, consisting of epithelial cells, mucus, and bile.
46
On examination, you notice a prominent bump to the left of midline on the topline of the hindquarters (croup). What is the most likely diagnosis?
sacroiliac luxation/subluxation
47
whats a good tx for a horse with sand enteropathies
The correct answer is psyllium. Psyllium is a hemicellulose laxative that has the ability to bind with sand and help remove it from the gastrointestinal tract. Feeding the horse in a stall and/or utilizing hay racks will also help the inadvertent consumption of sand that may be ingested if a horse is eating on sandy ground.
48
Any horse that has the hind limb in rigid extension and is unable to flex it should be suspected of having this problem. One condition that can mimic this gait is luxation of the coxofemoral joint which can lead to an inability to flex the hind limb but this can be distinguished clinically because the limb will not be extended.
upward patellar fixation. Most cases of upward patellar fixation can be managed conservatively (exercise (physical therapy), improved body condition). In severe and unresponsive cases, surgery to cut the medial patellar ligament is an option.
49
\_\_\_\_\_\_\_ is a term indicating stifle arthritis. It is nonspecific to the underlying cause and could be due to osteochondrosis, ligament injury, or some other problem.
Gonitis
50
there are 3 PA toxicity hallmarks we see in liver biopsy
megalocytosis, periportal fibrosis, and biliary hyperplasia
51
Osteochondrosis develops when there is abnormal ______ \_\_\_\_\_\_\_ resulting in the production of a cartilaginous flap within a joint. In young horses, a diagnosis is frequently made when first training. Severity of lameness can vary greatly. Osteomyelitis, trauma, and septic arthritis may be good differentials.
Osteochondrosis develops when there is abnormal endochondral ossification resulting in the production of a cartilaginous flap within a joint. In young horses, a diagnosis is frequently made when first training. Severity of lameness can vary greatly. Osteomyelitis, trauma, and septic arthritis may be good differentials.
52
What is the treatment of choice for a carpal hygroma in a horse?
The correct answer is surgical exploration and drain placement. A hygroma is a fluid filled swelling at the carpus, usually seen from repeated trauma leading to local bursitis. Horses are usually not lame from this condition but have restricted range of motion of the joint. Simply aspirating the fluid and/or injecting corticosteroids is rarely effective and the swelling usually recurs. Surgical excision of the bursal lining may be indicated when recurrence is a problem.
53
Fistulous withers refers to inflammation of the
Supraspinous bursa. Brucella abortus has been identified in up to 80% of clinical cases by serology and culture. Treatment consists of flushing the fistula and appropriate antibiotics.
54
The most common congenital cardiac abnormality in the horse is \_\_\_\_
Ventricular septal defect
55
Which antibiotic is contraindicated in foals?
The correct answer is enrofloxacin. Enrofloxacin is a fluoroquinolone and thus, its mechanism of action involves the inhibition of DNA gyrase. The reason you don't want to use it in foal is because it can result in arthrotoxicity and subsequent erosion of cartilage.
56
About what percentage of a horse's dry matter intake should be protein for an adult horse with maintenance requirements?
12%
57
what is normal PaCO2?
40
58
What is this ?
Thelazia (eyeworm). Adults are usually found in the eyelids, tear glands, tear ducts, or the nictitating membrane. They may be found in the eyeball itself under the conjunctiva or in the vitreous. Thelazia are transmitted by Diptera (flies) which do not bite but feed on tears.
59
Calcium carbonate stones in horses have a higher likelihood of forming in _____ urine
Calcium carbonate stones in horses have a higher likelihood of forming in alkaline urine
60
Strongylus vulgaris. A number of anthelmintics are effective including benzimidazoles, pyrantel and ivermectin.
61
Strongylus edentatus and Strongylus equinus have one BIG things in common, what is it
The L3 larvae migrate through the portal vein and into the liver, through the peritoneum and retroperitoneal space. After a few months, the larvae will then return into the lumen of the gut. Strongylus vulgaris will migrate through small vessels and into the cranial mesenteric artery.
62
where do Chorioptes equi mites like to hang out ?
around the foot and fetlock. It causes a pruritic dermatitis that can cause the formation of papules, crusts, thickened skin, as well as alopecia.
63
what are the signs associated with these toxicities ?
- St. John's wort
- Blue-green algae
- Slaframine
- cantharidin
St. John's wort acts as a primary photosensitizer and can lead to photophobia, conjunctivitis, sloughed skin, and icterus. Blue-green algae cause sudden death. Slaframine causes hypersalivation and cantharidin causes colic.
64
\_\_\_\_\_(breed) foals can develop combined immunodeficiency (CID) characterized by a lack of production of functional lymphocytes. No curative treatment exists, and foals will succumb to infection. In a CID foal, the foal typically has immunity from maternal antibodies for the first few months of life. However, as maternal antibodies begin to wane after 2-3 months, foals with CID will begin to develop recurrent infections that are responsive to antimicrobials. Once antimicrobials are discontinued, infection returns. Owners should be advised on the heritable nature of this disease. A genetic blood test is available to determine if a horse is a carrier of the CID trait.
Arabian foals can develop combined immunodeficiency (CID) characterized by a lack of production of functional lymphocytes. No curative treatment exists, and foals will succumb to infection. In a CID foal, the foal typically has immunity from maternal antibodies for the first few months of life. However, as maternal antibodies begin to wane after 2-3 months, foals with CID will begin to develop recurrent infections that are responsive to antimicrobials. Once antimicrobials are discontinued, infection returns. Owners should be advised on the heritable nature of this disease. A genetic blood test is available to determine if a horse is a carrier of the CID trait.
65
Centaurea solstitialis, aka yellow star thistle causes:
The loss of these upper motor ganglia results in loss of inhibition and dystonia, making it impossible for the animal to eat. Slow starvation results.
66
These are all flies that bug the horse, what does the horse show when they're around?
- Culicoides
- Tabanus flies and Chrysops
- Tabanus flies and Chrysops flies cause pain to horses by lacerating them with their mouth parts to feed on their oozing blood. They do not cause pruritus and can be differentiated by their large, robust size.
- Culicoides hypersensitivity is extremely pruritic and is also known as "sweet itch". Horses can be affected on their ventrum or dorsum
67
Which vx in the horse is associated with serum hepatitis
tetanus antitoxin. In horses previously immunized with tetanus toxoid, the tetanus antitoxin is contraindicated because of possible serum hepatitis. Tetanus antitoxin has been associated with fatal serum hepatitis, so its use should be restricted to horses with no prior history of vaccination with tetanus toxoid.
68
Oak poisoning in horses causes all the following except \_\_\_\_\_\_\_\_\_\_\_\_\_.
Colic
Renal failure Correct Answer
Death
Hemorrhagic diarrhea
Tenesmus
The correct answer is renal failure. Oak is the Quercus species and causes the clinical signs stated above. In cattle, it can cause renal damage (but not in horses). Treatment consists of supportive care.
69
when a farmer tells you his horse has "scratches" wtf does he mean ?
Scratches is a condition of chronic seborrheic dermatitis of the palmar/plantar aspect of the pastern. The condition is sometimes referred to by several other names including "grease heel", "dermatitis verrucosa", "dew poisoning" and "mud fever". It is not specific to the underlying infectious cause but the condition is generally associated with horses kept in wet or muddy environments.
70
wtf is "sweet itch"
Sweet itch results from a Type 1 allergic reaction to Culicoides spp. Clinical signs of sweet itch are usually in the form of self-trauma due to pruritus.
71
A 5-year old female Quarterhorse has been tentatively diagnosed with duodenitis-proximal jejunitis (DPJ). What other cause of equine colic can DPJ closely resemble?
Salmonella
Small intestinal obstruction
Ascarid impaction
Nephrosplenic entrapment
The correct answer is small intestinal obstruction. Both small intestinal obstruction and duodenitis-proximal jejunitis (DPJ) present with similar clinical signs. The problem is that a small intestinal obstruction will be a surgical disease, and duodenitis-proximal jejunitis responds better to medical treatment. The cause of duodenitis-proximal jejunitis remains unknown. Clinical signs include acute colic with increased respiratory rate, heart rate, and pain. Additionally, there will be lots of gastric reflux. After decompression of the stomach via nasogastric intubation and removal of excess gastric/intestinal fluid, horses with DPJ may appear much more comfortable.
72
What is the main disadvantage of giving xylazine to a horse with acute colic?
Laminitis
Inhibition of intestinal motility
Cardiac arrhythmias
Masking of clinical signs and the need for surgical intervention
The correct answer is inhibition of intestinal motility. When xylazine is given at 1.1 mg/kg it decreases the motility of the distal jejunum, cecum, and pelvic flexure for over 2 hours. Xylazine can also transiently decrease cardiac output in a potentially hypovolemic horse with colic.
73
Oleander is a ______ toxic
Astragalus is a _____ toxic
cardio - racing heart followed by low HR, arrhythmias, hyperK
Neuro - LOCOWEED causes cracker heels
74
75
Which of these drugs has the greatest potential for causing acute renal failure in the horse?
Doxycycline
Methoxyflurane
Phenylbutazone
Rifampin
The correct answer is phenylbutazone. Non-steroidal anti-inflammatory drugs such as phenylbutazone are known to cause acute renal failure in horses. The other big category of drugs known for causing acute renal failure is aminoglycosides.
76
Which of these findings would be expected in an endurance horse after a long race where it was sweating profusely?
Hyperkalemia
Metabolic alkalosis
Hyperchloremia
Hypercalcemia
Hypermagnesemia
The correct answer is metabolic alkalosis. Horse sweat is high in chloride (102 mEq/l), potassium (64 mEq/l), calcium, and magnesium. It is relatively normonatremic to plasma. They develop hypochloremic, hypokalemic metabolic alkalosis with low Ca and Mg. Renal retention of bicarbonate leads to the metabolic alkalosis.
77
What is true about regurgitation in horses with colic?
- Usually means a guarded to poor prognosis
- Occurs secondary to cecal impactions more often than small intestinal obstructions
- Is seen commonly
- Never associated with gastric rupture
correct answer is usually means a guarded to poor prognosis. Horses have an extremely tight lower esophageal sphincter tone and regurgitation will only occur when a very great pressure is exceeded. When this pressure is exceeded, there may be other damage such as gastric rupture. High pressure build up can occur with small intestinal obstructions. Cecal impactions are farther downstream and less likely to result in regurgitation.
78
Why are horses more predisposed to gastric ulceration as compared to other species?
They constantly secrete gastric fluid
They are easily stressed
They are hind gut fermentors
They have an underdeveloped gastric wall
They are predisposed to gastric reflux disease
The correct answer is they constantly secrete gastric fluid. This is unique to equids, as many other species only secrete gastric fluids in response to consumption of food items.
79
A 12-year old mare presents for infertility and abnormal sexual behavior. On rectal palpation, you feel a large multicystic ovary and the other ovary feels very small. What is the most likely diagnosis?
Ovaritis
Cystic ovarian follicles
Granulosa-thecal cell tumor
Ovarian hematoma
The correct answer is granulosa-thecal cell tumor. The clinical signs and palpation findings are both consistent with this diagnosis. The other choices listed may create a palpable ovarian mass but would not cause atrophy of the contralateral ovary and should not cause infertility.
80
You suspect equine infectious anemia is a cause of abortion in a mare. What test would confirm this diagnosis?
Direct Coomb's Test
Blood smear
Coggin's Test
Indirect Coomb's Test
Liver biopsy with immunofluorescent antibody
The correct answer is Coggin's test. This test is an agar immunodiffusion to detect serum antibodies against the retrovirus causing equine infectious anemia. Coomb's tests are done to diagnose immune mediated hemolytic anemias. The blood smear and liver biopsy would not show anything specific for equine infectious anemia.
81
A horse presents for ingestion of Jimsonweed which contains scopolamine. Which of the following is the treatment of choice against such an intoxicant?
Atropine
Epinephrine
Diphenhydramine
Physostigmine
Acetazolamide
The correct answer is physostigmine. Scopolamine is an atropine-like alkaloid and causes depression and is parasympatholytic to the autonomic nervous system. It can cause convulsions, respiratory failure, incoordination, mydriasis, and constipation. Treatment consists of activated charcoal, laxatives, diazepam to control convulsions and physostigmine (a parasympathomimetic).
82
Which of the following causes liver failure when ingested by horses?
Fiddleneck
Astragalus
Bracken fern
Oleander
The correct answer is fiddleneck. Fiddlenecks contain pyrrolizidine alkaloids as does groundsel, ragwort, and senecios. Pyrrolizidine alkaloids cause secondary photosensitization as well as hepatic damage that are cumulative and progressive. Treatment consists of supportive care for liver failure and prognosis is poor.
83
What does intoxication with these things cause?
- castor bean
- sweet pea
- red maple
- senecio/ groundsel
- black walnut
- castor bean: severe GI irritation and hemorrhagic diarrhea
- sweet pea: horse develops stringhalt
- red maple: associated with hemolytic anemia
- senecio/ groundsel: associated with liver disease after chronic exposure.
- black walnut: laminitis and colic
84
A horse presents to you with signs of fistulous withers. From where is this condition most likely contracted?
Contaminated feed
Infected sheep
Infected cattle
Contaminated soil
the correct answer is infected cattle. The causative agent of fistulous withers is Brucella abortus, and it usually is transmitted to horses by infected cattle.
85
A horse is referred to your practice for further evaluation and treatment of glomerulonephritis. Which of the following is not a treatment option?
Long term furosemide administration
Low protein diet
Corticosteroids
Plasma transfusion
The correct answer is long term furosemide administration. Horses with glomerulonephritis are usually polyuric. Furosemide is only indicated for oliguric renal failure. The other choices are commonly used in the treatment and management of glomerulonephritis. A low protein diet will help decrease the amount of proteinuria and blood urea nitrogen circulating at any given time, therefore helping reduce the degree of azotemia.
86
About what percentage of a horse's dry matter intake should be protein for an adult horse with maintenance requirements?
24%
6%
18%
30%
12%
The correct answer is 12%. A horse requires about 1.3 g protein per kilogram body weight or about 40 g of protein per 1000 calories. This corresponds to about 12% of dry mater intake. Obviously, other factors play some role, including the quality of the protein source. In general, excess protein does not cause horses any health problems, but it can be an unnecessary expense for owners. Too little protein can result in malnutrition problems.
87
A horse gets into cow feed that contains the ionophore, monensin. What is your biggest concern?
The correct answer is cardiotoxicity. Monensin is a coccidiostat used to increase productivity in cattle. Horses are much more susceptible to toxic effects of monensin than cattle and mistakes in feeding or accidental access to cattle feed can lead to toxicity. Monensin toxicity results in myocardial necrosis and development of dilated cardiomyopathy in horses. Clinical signs include progressive respiratory distress, heart murmur, weakness, and hypovolemic shock. Acutely, mild colic and diarrhea can occur as well but is less of a concern than the cardiovascular effects.
88
Which of these tests is most reliable in diagnosing a uterine infection in a mare?
Uterine cytology
Uterine culture
Complete blood count
Cervix culture
The correct answer is uterine cytology. Endometrial cytology will show a more quantitative measure of not only bacteria but of leukocytes. Because there are many commensal organisms found in and around the uterus, culture is neither sensitive nor specific. However, it is often a worthwhile test to determine what organisms are there and to design an appropriate antibiotic plan based on susceptibility results. A cervical swab is less reliable than an endometrial sample. CBC is neither sensitive nor specific for diagnosing endometritis. The presence of a high percentage of neutrophils in an endometrial cytology is very suggestive of uterine infection, especially if bacteria are also seen.
89
TERMANOLOGY
- Scratches
- Summer sores
- Sweet itch
- Sweeney
- Ringbone
Scratches is a condition of chronic seborrheic dermatitis of the palmar/plantar aspect of the pastern. The condition is sometimes referred to by several other names including "grease heel", "dermatitis verrucosa", "dew poisoning" and "mud fever". It is not specific to the underlying infectious cause but the condition is generally associated with horses kept in wet or muddy environments.
Summer sores are caused by Habronema spp. and Draschia spp. stomach worms of the horse. The larvae in feces are ingested by the maggots of flies, and the flies can deposit them at susceptible moist skin areas, damaged skin areas, or mucous membranes where the larvae cause an eosinophilic granuloma as a reaction to their migration.
Sweet itch results from a Type 1 allergic reaction to Culicoides spp. Clinical signs of sweet itch are usually in the form of self-trauma due to pruritus.
Sweeney is the common name for shoulder atrophy in the horse. The muscle atrophy is caused by damage to the suprascapular nerve which innervates to the infraspinatus and supraspinatus muscles.
Ringbone refers to osteoarthritis or bony exostosis in the pastern (high ringbone) or coffin (low ringbone) joints.
90
What body systems are most affected in an anaphylactic reaction in a horse?
Lungs and colon
Heart and small intestine
Kidney and colon
Liver and lungs
Liver and kidneys
The correct answer is lungs and colon. These are referred to sometimes as the shock organs in the horse. When a horse undergoes an anaphylactic reaction from an allergen or chemical stimulus, the primary signs will be respiratory and lower GI and will include dyspnea or severe respiratory distress and diarrhea. Other common signs include anxiety, tachycardia, piloerection, and sweating. Treatment of anaphylactic shock usually includes injection with some combination of epinephrine, corticosteroids, and an antihistamine.
91
Equine herpesvirus-3 (coital exanthema) is a cause of which of the following?
Infertility in mares
Balanoposthitis
Abortion
Infertility in stallions
The correct answer is balanoposthitis. EHV-3 causes papules, pustules, and ulcers to the vestibular mucosa, vulvar skin, and the penis and prepuce (balanoposthitis). Less frequently, it can involve the skin of the face. There are no systemic signs or consequences of the infection, although secondary bacterial infections are possible. Spontaneous recovery usually occurs over about 2 weeks, and no treatment is usually required except sexual rest to prevent spread as balanoposthitis is venereally transmitted.
92
Which of the following parameters is NOT associated with a diagnosis of DIC?
## Footnote
Prolongation of Prothrombin Time (PT)
Elevation in D-dimers
Abbreviated (shortened) activated partial thromboplastin time (aPTT)
Decreased antithrombin III activity
Thrombocytopenia
Disseminated intravascular coagulation is a complex disorder that can be described as widespread activation of the coagulation system, resulting in a pro-coagulant state with systemic thromboses and secondary diffuse hemorrhage throughout the body. DIC is secondary to pathologic conditions such as sepsis, localized infections, colitis, neoplasia, trauma, hepatic or renal failure, vasculitis, and various other disorders. DIC is associated with thrombocytopenia (from platelet consumption), prolongation of coagulation times such as PT and aPTT (from consumption of coagulation factors), elevations in D dimers (from degradation of fibrin), and low antithrombin III (from consumption). Thus the correct answer to this question is shortened aPTT. These criteria for DIC apply to all species, not just horses.
93
An 8-year old horse presents for evaluation of ear lesions. On examination, you note coalescing depigmented and hyperkeratotic plaques on the inner (concave) surface of the pinna bilaterally. Which of the following treatments is most likely to result in regression of the lesions?
Environmental insect control
Systemic antibiotics
Systemic glucocorticoids
Topical imiquimod (Aldara)
Aural plaques in horses are caused by papillomavirus and are mechanically spread by insects such as black flies. Lesions do not typically regress but topical application of imiquimod cream was efficacious in causing resolution of the lesions. Environmental insect control is also a wise recommendation in this case but would not lead to regression of the lesions. Systemic antibiotics or glucocorticoids would not be effective against this viral lesion but glucocorticoids are sometimes used to control clinical signs (pruritus) seen concurrently with these lesions.
94
Fescue ingestion leads to
Red maple causes
St John's wort causes
Pyrrolizidine alkaloids
Cantharidin causes
Fescue ingestion leads to prolactin suppression and can result in thickened placenta, dystocia, or agalactia. Red maple causes Heinz body anemia. St John's wort causes photosensitization and hepatotoxicity. Pyrrolizidine alkaloids cause photosensitization and hepatotoxicity. Cantharidin causes colic.
95
What are the three diagnostic parameters that horses need to meet in order to go to isolation ?
Diarrhea, fever, and neutropenia. Any 2 of the 3 diagnostic parameters qualify for isolation.
96
You are presented with a 6-month old colt with a 5-day history of lethargy, intermittent diarrhea, weight loss, and ventral edema. A quick check of the PCV and TP reveal a PCV of 30% (28-42%) and TP of 3.2 g/dl (6.8-8.2 g/dl). Abdominal ultrasound (see image) demonstrates thickening of the small intestinal wall. What is the most likely diagnosis based on signalment, history and clinical findings?
## Footnote
Intermittent jejunal intussusception
Clostridium difficile enteritis
Salmonella infection
Lawsonia intracellularis infection
Although not as commonly as in pigs, L. intracellularis can infect horses (and other species). Similar to pigs, the infection usually involves weanling age horses and causes thickening of the small intestine and hypoproteinemia. The low protein is commonly observed as ventral edema clinically. Both Clostridium and Salmonella can cause diarrhea at any age but are not as commonly associated with ventral edema. Intussusceptions do occur but also typically result in colic.
97
Claviceps purpura is the causative agent for which of the following?
Aflatoxicosis
Ergotism
Moldy sweet clover poisoning
Moldy corn poisoning
The correct answer is ergotism. Claviceps purpura is a parasitic fungus found on rye, oats, wheat, and Kentucky bluegrass. Its toxicity comes from alkaloids and causes vascular constriction, thrombosis, gangrene, and vomiting, colic, diarrhea, and constipation. Diagnosis is made by identifying ergot on the grain.
98
Which of these is least likely to cause oligozoospermatism in a stallion?
Acute orchitis
Testicular hypoplasia
Old age
Testicular degeneration
The correct answer is orchitis. Acute orchitis tends to cause morphologic or motility abnormalities in sperm but usually will not cause oligozoospermatism or decreased numbers of sperm. Chronically, fibrosis and testicular atrophy can occur which may cause oligozoospermatism.
99
A 3 month old Arabian foal presents for a progressive onset of intention head tremors, ataxia, dysmetria, and spasticity. On physical exam, the foal is noted to have proper mentation and is not weak. Heart rate, respiratory rate, and temperature are within normal limits. Given the signalment and presentation, what is the most likely diagnosis?
Cerebellar dysplasia
Sarcocystis neurona
Inner ear disease
Cerebellar abiotrophy
The correct answer is cerebellar abiotrophy. Cerebellar abiotrophy is usually observed in foals which are less than one year of age, particularly 1-6 months of age. Cerebellar abiotrophy is the most common cerebellar disease found in horses. It is mostly seen in Arabian, Oldenburg, and Gotland breeds. There is no treatment, and signs may be progressive. Diagnosis is based on a good history and clinical signs such as intention tremors, lack of a menace, hypermetria, and ataxia.
100
Which of the following is not a common clinical sign of urolithiasis in horses?
Polyuria
Dysuria
Hematuria
Pollakiuria
The correct answer is polyuria. Dysuria, pollakiuria, and hematuria all can commonly occur with uroliths in the bladder or uroliths lodged in the urethra. Polyuria does not occur typically with urolithiasis in horses.
101
Which of the following is not believed to be a cause of physitis in young horses?
Osteochondrosis
Growth plate compression
Conformational defects
Malnutrition
Abnormal hoof growth
The correct answer is osteochondrosis. Physitis in young horses involves swelling around growth plates in long bones. Physitis is sometimes thought to be a component of osteochondrosis, but the other answer choices have been suggested to be causes of physitis.
102
fiddleneck consumption causes ...
The correct answer is megalocytosis, fibrosis, and biliary hyperplasia of the liver. Fiddleneck (Amsinckia intermedius) is a pyrrolizidine alkaloid. Nigropallidal encephalomalacia is seen as a result of consuming yellow star thistle.
103
Total parenteral nutrition (TPN) can be administered to patients that cannot tolerate oral feeding. Sterility and catheter care must be rigorous due to the excellent bacterial growth potential of your TPN solution. The building blocks of \_\_\_\_\_, _____ ,\_\_\_\_\_\_
Total parenteral nutrition (TPN) can be administered to patients that cannot tolerate oral feeding. Sterility and catheter care must be rigorous due to the excellent bacterial growth potential of your TPN solution. The building blocks of carbohydrates, proteins, and fat are key components. (Dextrose, amino acids, and lipids)
104
What are the two most common NSAID toxicoses seen in the horse?
Renal papillary necrosis and right dorsal colitis
105
Equine viral arteritis can be transmitted by which of these routes?
Fecal-oral
Through open wounds
Venereally
Blood-sucking arthropods
The correct answer is venereally. Carrier stallions can infect mares. It can also be spread by aerosol. Equine viral arteritis (EVA) is in the genus Arterivirus, family Arteriviridae and causes vasculitis leading to edema, conjunctivitis, rhinitis, and abortion.
106
Which of the following is not a cause of dysphagia in the horse?
Bracken fern
Guttural pouch infection
Lead poisoning
Yellow star thistle poisoning
The correct answer is bracken fern. Bracken fern will result in thiamine deficiency
107
Which medication would be appropriate to administer to promote hemostasis?
Low-Molecular Weight Heparin (LMWH)
Aspirin
Aminocaproic Acid
Tissue Plasminogen Activator (tPA)
Aminocaproic acid is the only anti-fibrinolytic medication listed that may promote hemostasis. Aminocaproic acid binds and inhibits plasminogen activation thereby promoting clot maintenance and stabilization. The other medications would be considered fibrinolytics (tPA) or anti-coagulants (LMWH, aspirin).
108
An 11-month old Paint gelding is presented to you for symmetric ataxia, weakness, and spasticity of all limbs. When walking, the hind limbs frequently interfere with one another. Based on the signalement, history, and physcial examination findings, you suspect equine degenerative myeloencephalopathy (EDM). What diagnostic test would you use to support your suspicion?
There is no definitive antemortem test for EDM; it can only be confirmed through histopathologic examination of the spinal cord and brainstem and the identification of diffuse neuronal fiber degeneration of the white matter. However, many cases of EDM have been associated with low serum vitamin E concentrations, so measurement of vitamin E is suggestive of disease. The exact etiology of EDM is unknown, however, oxidative stress and damage to the central nervous system is a prominent theory.
109
A 23 year old horse is most likely to have what type of valvular regurgitation?
Aortic regurgitation
Tricuspid regurgitation
Pulmonic regurgitation
Mitral regurgitation
The correct answer is aortic regurgitation. Degeneration of the aortic valve is the most common reason for aortic regurgitation and is present in a lot of older horses as an incidental finding. On auscultation you will hear a holodiastolic murmur with a point of maximum intensity over the aortic valve area.
110
Which of these vaccines administered intramuscularly is most likely to cause a local reaction at the injection site of a horse?
Historically, an intramuscularly administered Strangles vaccine has been available and has been associated with soft tissue reaction. More recently, an intranasal vaccine has become available, which is associated with local protection without any injection reaction.
111
You are examining a 3 year old Thoroughbred gelding that just completed a race and notice discharge from the nostrils (see image). What would be an appropriate treatment for this horse prior to the next race?
In this instance, the discharge is blood, with the most likely diagnosis being exercise-induced pulmonary hemorrhage (EIPH). One of the most commonly administered medications for EIPH is furosemide, which seems to decrease the incidence or lessen the severity of bleeding. The exact mechanism by which this occurs is not completely known but may be associated with reduced pulmonary capillary pressure.
112
Cerebellar _______ is usually observed in foals which are less than one year of age, particularly 1-6 months of age. Cerebellar ________ is the most common cerebellar disease found in horses. It is mostly seen in Arabian, Oldenburg, and Gotland breeds. There is no treatment, and signs may be progressive. Diagnosis is based on a good history and clinical signs such as intention tremors, lack of a menace, hypermetria, and ataxia.
Cerebellar abiotrophy
113
What is the normal blood lactate in a healthy foal or horse?
Less than 5 mmol/L
Less than 10 mmol/L
Less than 2.5 mmol/L
Less than 7.5 mmol/L
Less than 2.5 mmol/L
114
What is the most common cause of maxillary sinusitis in a horse
Tooth root abscess
115
Sesamoiditis is usually caused by which of the following in horses?
Extension of tendonitis
Chronic sesamoid fractures
Penetrating wounds
Tearing of the ligamentous attachments to the sesamoids
Septicemia
The correct answer is tearing of the ligamentous attachments. During strenuous exercise, the insertion of ligaments on sesamoid bones can tear, leading to sesamoiditis. Clinical signs can be similar but are generally less severe than sesamoid fractures (lameness, inflammation). Radiographic findings in sesamoiditis can include new bone formation or osteolytic lesions and radiolucent lines which are prominent vascular channels. Treatment involves long term rest and NSAIDs. Prognosis is guarded to poor.
116
Approximately how long does it take for spermatogonia to mature to sperm in the stallion?
60days
117
What is the most common cause of blindness in horses?
Equine recurrent uveitis
Cataract(s)
Trauma
Bacterial ulcerative keratitis
Fungal ulcerative keratitis
Although all of the listed answers could potentially result in blindness (directly or as a result of enucleation), the most common cause of blindness in horses is equine recurrent uveitis (ERU). This disease is also known as moon blindness or periodic ophthalmia. Recurrent episodes may result from dysregulated immune responses within the eye; typical clinical signs include blepharospasm, photophobia, lacrimation, miosis and aqueous flare.
118
Approximately how long does it take for spermatogonia to mature to sperm in the stallion?
The correct answer is 60 days. For this reason, a stallion with poor quality semen should be re-evaluated in 2 months before making a final judgment.
119
How is equine viral arteritis transmitted?
Venereally
Tick
Transplacentally
Mosquito
The correct answer is venereally. EVA may also be transmitted via aerosolized secretions. Most infections are asymptomatic in adults, but clinical signs may include fever, lethargy, anorexia, edema, oculo-nasal discharge, and petechia. In foals, severe respiratory distress, leukopenia, thrombocytopenia, and death after 12-24 hours can occur.
120
Which of the following is the best recommendation for preventing transmission of African Horse Sickness ?
* Treat all horses with oxytetracycline because the etiologic agent is exquisitely sensitive to this antibiotic
* Separate all horses from each other and all other animals because horses are most commonly infected by direct contact with infected animals
* Institute strict arthropod control measures because the disease is transmitted primarily by Ixodes ticks
* Stable all horses in insect-proof housing, particularly at night because the disease is transmitted primarily by Culicoides flies
* The owner should not travel to any of the states where the disease is present because the virus is transmitted by fomites and can survive for extended periods
transmitted by insects, primarily Culicoides.
African horse sickness is endemic in sub-Saharan Africa and outbreaks have periodically extended to the Middle East and southern Spain. The primary and biological vector is Culicoides but the virus may also be transmitted by mosquitoes. The virus has been isolated from certain ticks but arthropod transmission is not believed to play a significant role.
Clinical signs of AHS typically develop 5-7 days after infection and begin with fever and conjunctivitis. Some animals may recover but many go on to develop the pulmonary and/or cardiac forms of AHS. The pulmonary form consists of acute respiratory distress, coughing, sweating, and foaming from the nostrils; this form is usually fatal. The cardiac form consists of edema of the head and neck as well as abdominal pain and depression. A characteristic sign is swelling in the indentation above the eyes (also referred to as swelling of the supraorbital fossa). About 50% of animals with the cardiac form die from heart failure while the rest gradually recover after about one week.
Diagnosis can often be made based on history of exposure to endemic areas, clinical signs and lesions but must be confirmed by viral isolation and/or serology. There is no effective treatment and prevention/control can be accomplished by vector control and vaccination. There are multiple serotypes of virus and animals immunized against certain serotypes are still susceptible to others. In an outbreak situation, affected horses should be removed/euthanized and remaining horses should be vaccinated with a polyvalent vaccine until the specific serotype can be determined and then animals should be revaccinated with the corresponding vaccine.
For importing equids from Africa, a 2 month quarantine is required and then horses must test free of virus. Presence of antibodies does not disqualify a horse from importation. Because of the vector-borne nature of the disease, it is recommended that planes flying from endemic areas be sprayed with insecticides on arrival to disease-free countries.
121
What breed of horse is predisposed to development of recurrent uveitis and equine night blindness?
Arabian
Quarterhorse
Thoroughbred
Appaloosa
The correct answer is Appaloosa. Equine night blindness is a congenital disease that is bilateral and nonprogressive, wherein horses have variable degrees of decreased vision in the dark. Recurrent uveitis is a very important condition in the horse and is actually the most common cause of blindness in the horse. Appaloosas are overrepresented, but the disease can occur in any breed. It is thought to be related to certain pathogens including Leptospira, Onchocerca, Toxoplasma, Brucella, and other infections, but these relationships are poorly characterized. Affected horses have recurrent bouts of inflammation, and each episode causes progressively worsening intraocular damage. The condition is sometimes referred to as moon blindness.
122
Which of the following larvae is known to migrate through the portal vein and into the liver of a horse?
Anoplocephala perfoliata and Strongylus vulgaris
Strongylus edentatus and Strongylus vulgaris
Strongylus vulgaris and Strongylus equinus
Strongylus edentatus and Strongylus equinus
The correct answer is Strongylus edentatus and Strongylus equinus. The L3 larvae migrate through the portal vein and into the liver, through the peritoneum and retroperitoneal space. After a few months, the larvae will then return into the lumen of the gut. Strongylus vulgaris will migrate through small vessels and into the cranial mesenteric artery. Anoplocephala perfoliata is a tapeworm and does not migrate through blood vessels.
123
The most common conduction disorder in the horse occurs at the level of the \_\_\_\_\_\_\_\_\_.
Purkinje fiber system
Atrioventricular node
Bundle of His
Sinoatrial node
The correct answer is the atrioventricular node. At the atrioventricular node, we see first-degree AV blocks, second-degree AV blocks, and third-degree AV blocks.
124
How much time is required for complete healing of tendon injuries in the horse?
8-11 months
13-14 months
2-3 months
Tendons never heal
4-5 months
The correct answer is 8-11 months. Tendonitis involves stretching of the collagenous fibers resulting in tearing and hemorrhage. Secondarily, inflammation occurs and a compartment syndrome may occur. Neovascularization and granulation tissue replace the clot and fibroblasts produce new tendon and collagen. The newly formed type III collagen is eventually replaced by type I collagen; however, the replacement is never complete. This process takes between 8-11 months.
