Bovine

Question 1

Trismus

Answer 1

• Trismus, also called lockjaw, is reduced opening of the jaws (limited jaw range of motion). It may be caused by spasm of the muscles of mastication or a variety of other causes.

Question 2

What causes Tetanus?

Clinical Signs?

Answer 2

• Clostridium tetani
• Classic clinical signs include a sawhorse stance, lockjaw, and an elevated tail (“pump handle tail”)
• These animals are especially sensitive to tactile and auditory stimuli.
• Infection was probably through inoculation of a wound.
• However, there is evidence that infection may occur via ingestion

Question 3

When formulating late gestation anionic diets for dairy cows to help prevent hypocalcemia in the last 2 to 3 weeks prior to calving, what formula is used?

Answer 3

DCAD = (Na + K) - (Cl + S)

• DCAD stands for Dietary Cation Anion Difference.
• Na=sodium, K=potassium, Cl=chloride, and S=sulfur.
• These are the 4 most important strong ions to be considered.
• When the diet is optimal the urine pH of Holstein cows should range between 6.2 and 6.8 for cows on the ration

Question 4

Desribe the disease processs in adult cattle from Clostridium hemolyticum

(recently renamed C. Novyi Type D)

Treatment?

Answer 4

• Bacillary haemoglobinuria
• Infection of the liver by migrating flukes (Fasciola hepatica), results in anaerobic tracks that allow the Clostridium to bloom and cause disease
• NOT the same as C. Novyi Type B - causing “Black Disease” (Infectious Necrotic Hepatitis) - pathogenesis is similar!
• Treat with penicillin or oxytetracycline​

Question 5

Persistent infection of a bovine fetus with Bovine Viral Diarrhea (BVD) virus is most likely to occur when the non-immune dam is viremic with a non-cytopathic biotype of BVD at what stage of gestation?

Answer 5

• At 50 to 150 days gestation, the fetal immune system does not recognize the BVD virus as foreign and becomes persistently infected

Question 6

Bovine Urolithiasis

What can it often lead to? Clinical signs of this phenomena?

Answer 6

• In the bovine, urolithiasis often results in rupture of the urethra.
• Urine then leaks into all the ventral tissues and causes this massive ventral edema, which progresses to necrosis and sometimes to gangrene
• may see: poor appetite, depressed attitude, and ventral swelling (pitting ventral oedema)

Question 7

A 4 month old Holstein calf presents with a right sided head tilt, a unilateral right ear droop, right eye ptosis and epiphora of the right eye. Otherwise, the calf is bright and alert. The owner mentioned that the calf suffered from a respiratory infection the previous week.

What is the most likely diagnosis?

What is the most common cause? (pathogen)

Most common source of infection?

Answer 7

• Otitis media-externa
• Mycoplasma is a common cause of otitis media-externa
• Usually, the infection is a result of consuming contaminated milk

Question 8

What is Otobius Megnini?

good differential diagnosis for?

Answer 8

• Otobius is a soft tick with predilection for ears - SPINOSE EAR TICK
• it is a good differential for otitis media - externa
• With Otobius the calf would probably not show such extreme clinical signs and would probably be scratching and rubbing at the ear

Question 9

Polioencephalomalacia

What is it caused by?

List some clinical signs

Differential Diagnoses? (2)

Answer 9

• Polioencephalomalacia is more likely to present with stargazing, head pressing, depression, and blindness.
• Polioencephalomalacia is caused by a thiamine deficiency
• An excellent differential for the clinical signs described would be listeriosis and thromboembolic meningoencephalitis.

Question 10

Regarding normal reproductive physiology, the cow differs from the sow, the mare, the ewe, and the nanny/doe in which of the following ways?

Which are seasonal breeders?

Which have an epithelio-chorial placenta?

Which species is in oestrus often for more than 5 days?

Answer 10

• An unusual feature of bovine reproductive physiology is the fact that the cow ovulates after she goes “out” of estrus. The practical implication of this is that one can successfully breed by artificial insemination later, relative to estrus.
• The mare, the ewe, and the nanny/doe are all seasonal breeders, but generally, the cow is not.
• All the animal species listed in the question have an epithelio-chorial placenta.
• Although twin births do occur in a minority of cows, the cow normally ovulates a single oocyte per cycle, as does the mare. Sheep and goats have been selected for fecundity, with the result that multiple ovulations/cycle are the rule, rather than the exception. Litter-bearing pigs ovulate large numbers of oocytes per estrous cycle.
• The sheep and goat are in estrus for only 1.5-3 days; the pig is similar. Only the mare, of the species listed, is physiologically in estrus for 5 days or more.

Question 11

Is Brucellosis a notifiable disease in the United States?

Answer 11

A: Yes

• after a positive milk ring test, It is reported to state and all of the cows will be serologically tested within 30 days, reactors will be slaughtered
• Brucellosis is a reportable disease and is promptly reported to the appropriate agency in the state. Positive animals should be slaughtered, not treated.

Question 12

What is this 1/2 inch grub that emerge from the back of cattle in spring?

Answer 12

• This is a cattle warble called Hypoderma.
• The 2 species are H. bovis and H. lineatum.
• They undergo a long migration in tissues and only emerge from the back of the animal in spring.
• The crucial treatment time is early fall when larvae are just beginning to migrate in tissues.
• Organophosphates or one of the macrocyclic lactones (ivermectin, doramectin, eprinomectin or moxidectin) are effective.

Question 13

You are working with a farmer who is having trouble with calves between the age of 2 weeks and 6 months. They are alert, but weak, dyspneic and die suddenly. On necropsy they have pale cardiac and skeletal muscles. What is the farmer’s problem?

Answer 13

• Selenium Deficiency - “white muscle disease”
• The pale muscle and clinical signs are classic for vitamin E and selenium deficiency.
• This is important to remember!
• Other things that should be on your differential list for this case include cardiotoxic plants. - Milkweed, bacharris spp., etc.

Question 14

Answer 14

• Struvite
• Struvite is composed of magnesium ammonium phosphate.
• The alkaline urine in cattle along with high dietary phosphate and magnesium levels favors formation of struvite stones.
• Feedlot animals can also develop apatite stones composed of calcium phosphate.

Question 15

Where would you find the following uroliths in livestock animals?

Silicate?

Calcium Carbonate?

Calcium Oxalate?

Answer 15

• Silicate stones are primarily found in sheep and cattle grazing western rangelands.
• Calcium carbonates are most commonly found in sheep grazing pastures high in calcium and oxalates.
• Calcium oxalate crystals are often present in ruminant urine and may be incorporated in small amounts into other types of stones.

Question 16

What are benefits of of providing a DCAD (dietary cation-anion difference) diet to cattle?

Answer 16

• cows absorb calcium more readily
• cows remain more relatively acidotic
• There is a lower incidence of milk fever
• parathyroid hormone function is enhanced
• DCAD is used to help prevent milk fever. Cows eating a DCAD diet are actually more acidotic which enhances parathyroid hormone function along with a better ability to utilize dietary calcium. The easy measure is to check urine pH (it should be acid) on cows to be sure they are ingesting the diet.
• To review, DCAD is dietary cation-anion difference. A DCAD diet is enhanced with more anionic salts containing the strong ions chloride and sulfur, and has decreased amounts of strong cations such as sodium and potassium.
• Cations have a positive charge like sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg).
• Cations in the diet promote a more alkaline (higher blood pH) metabolic state which has been associated with an increased incidence of milk fever.
• Anions have a negative charge such as chloride (Cl), sulfur (S) and phosphorus (P).
• Anions promote a more acidic metabolic state (lower blood pH) that is associated with a reduced incidence of milk fever.
• A cow adjusts to a lower blood pH by buffering the acidic condition.

Buffering the blood is done by the cow through mobilization of calcium phosphate from bones. When a lower pH is achieved by feeding more anions, the result causes the cow to mobilize stored calcium which can better prepare her for the time when calcium will be lost in milk. This is the reason that there are various anionic products on the market: to reduce the incidence of milk fever

Question 17

Presence of dysphonia may indicate a lesion in __________.

Answer 17

CN X

Clinical signs of lesions of the vagus nerve include dysphagia, abnormal vocalizing, inspiratory dyspnea, and megaesophagus.

Question 18

Bovine leukocyte adhesion deficiency

(BLAD)

Answer 18

• in Holstein Cattle
• autosomal recessive congenital disease characterized by recurrent bacterial infections, delayed wound healing and stunted growth, and is also associated with persistent marked neutrophilia
• The most common inheritance pattern of genetic disease in cattle is a simple recessive trait. The defective calf receives a recessive gene from its sire and dam.
• An autosomal recessive disorder means two copies of an abnormal gene must be present for the disease or trait to occur.

Question 19

Answer 19

• Surgically remove the intussusception and anastomose the ends of the intestine
• Cows with intussusception usually have colic, scant dark red feces, dilated small bowel proximal to the lesion, and a distended abdomen from accumulated fluid in the proximal gut and forestomachs.
• They may also have a fever if there is leakage and peritonitis is developing.
• The lesion is sometimes palpable per rectum. They are most commonly suffering from hypochloremic hypokalemic metabolic alkalosis

Question 20

You are called out to a dairy herd that has recently been experiencing reproductive problems. The cows were all acquired 1 year ago from an unknown source and have no known vaccinations or tattoos. The dairyman reports that several cows have had late abortions (6-7 months gestation) and weak or stillborn calves in the past year and he’s never had this problem before. Several of the cows that had abortions developed placental retention and/or metritis. None of the younger pre-pubescent heifers are displaying any clinical signs. You perform a necropsy on two recently aborted fetuses and find lung consolidation in one but no other obvious abnormalities.

What should you recommend?

Answer 20

• Serologic testing for Brucellosis
• You should be most suspicious of Brucellosis based on the assortment of signs (abortions, retained placenta, metritis and lack of signs in younger animals), the timing of abortions (last half of pregnancy), and the relatively normal appearance of the examined fetuses.
• Plus the cattle are not tattooed as they should be if they were given calfhood brucella vaccine.

Question 21

When do Tritrichomonas fetus abortions generally occur in cattle?

Answer 21

• first half of gestation
• but do have placentitis and pneumonia in the fetus similar to Brucella abortions

Question 22

Campylobacter fetus subsp venerealis in cattle

Answer 22

• It causes catarrhal inflammation in the female genital tract, temporary infertility and prolonged oestrus cycle
• usually causes early embryonic death
• strict international regulations require animals and animal products to be CFV-free for trade

Question 23

Neopspora Abortions

Answer 23

• Neospora Caninum is a protozoan parasite that is an important infectious cause of weak calves and abortion in cattle.
• It can affect other species including sheep, goats and camelids, however these are thought to be less susceptible.
• Neospora is the most frequently diagnosed cause of bovine abortion
• Neospora abortions are usually mid gestation and cause necrosis of the cotyledons, with fetal lesions including myocarditis, hepatitis, myositis and encephalitis

Question 24

Brucellosis

Describe?

Symptoms?

Diagnosis?

Answer 24

• Brucellosis is an infectious disease that occurs from contact with animals carrying Brucella bacteria.
• Brucella can infect cattle, goats, camels, dogs, and pigs.
• The bacteria can spread to humans if you come in contact with infected meat or the placenta of infected animals, or if you eat or drink unpasteurised milk or cheese.
• Brucella is highly contagious, spreading very easily between cattle as the calf, the membranes and the uterine fluids all contain large quantities of bacteria

Symptoms

• Abortion;
• Stillborn
• Weak calf born
• Retention of fetal membranes;
• Signs of infection in the membranes;
• Swollen testicles in bulls
• Infection of the testicles is also seen in bulls.

Diagnosis can be done by laboratory testing of blood or milk samples or by laboratory culture of brucella abortus from the placenta, vaginal discharge or the milk of infected cows.

Question 25

Gestation of a cow? What positive pregnancy diagnosis sign is present at 30 days? 75-90 days? 4-7 months? Uterine artery fremitus?

Answer 25

* **283 days** * **Chorioallantoic membrane slip​ present at 30 days** * **Placentomes** will be palpable starting between **75-90** days of gestation. * The fetus itself will be palpable beginning at approximately **60 days gestation**, but may be out of reach between months **4-7 of gestation**. * **Uterine artery fremitus (palpable turbulence)** will be evident on the ipsilateral pregnant horn at about **120 days of gestation.** * From 7 months on, you can feel the fremitus bilaterally. Fremitus does not necessarily always indicate a viable pregnancy

Question 26

Rectal Temperature of Cow Normal? calf?

Answer 26

* rectal temperature reference range for an adult cow is **37.8-39.2°Celsius** [100.0-102.5°Fahrenheit], * little higher for a calf at **38.6-39.4°**Celsius [101.5-103.5°Fahrenheit].

Question 27

Radial Nerve Disease - what would the presentation involve? What would you see with the other thoracic limb nerves?

Answer 27

* With radial nerve disease, the elbow is dropped, the digits are knuckled onto their dorsal surface, and the limb is unable to bear weight. * With time, the **triceps and carpal extensor muscles** may also atrophy in radial nerve disease. * Note: With injury to the **suprascapular nerve**, the supraspinatus and infraspinatus muscles are atrophied, but little gait deficit is noted. **Musculocutaneous nerve** injury results in an inability to flex the elbow and biceps atrophy. With lesions to the **ulnar nerve,** superficial and deep digital flexor muscles atrophy

Question 28

Thoracic Nerve Placement canine equine bovine

Answer 28

Question 29

At what age during gestation is a fetus most likely to become **persistently infected** with the noncytopathic form of **bovine viral diarrhea?**

Answer 29

* The correct answer is **fetus infected before 125 days of gestation, with most of those occurring before 100 days**. * A fetus infected with BVD at any time during gestation can be aborted or be a stillbirth. * Most congenital defects associated with BVD occur when a fetus is infected between days 90-150 of gestation. * Persistent infection of fetuses is seen when they are infected before 125 days of gestation. This is of importance because they have a potential to affect many other herdmates since they shed virus but may show no clinical signs. * About half of the persistently infected calves will die during their first year of life. Clinical signs in BVD carriers vary greatly. They may range from an asymptomatic animal to one that has diarrhea, fever, pneumonia, and oral ulcerations. * Additionally, you may have infected animals that are just repeat breeders. You may also see abortions, stillbirth, and congenital anomalies. The most common congenital anomaly associated with BVD is **cerebellar hypoplasia,** but there are many others.

Question 30

Heart Rate of Adult Cow

Answer 30

The adult cow has a heart rate of between **48 and 84 beats per minute**

Question 31

About 1 hour after a difficult labor where the calf had to be pulled out with force, the cow goes down. She is **pale and her heart rate is 100/min**. What happened?

Answer 31

* **uterine tear.** * With a traumatic fracture or damage to nerves, the cow would have gone down right away rather than an hour later. * Hypocalcemia is possible but less likely in this case where the calf had to be forcibly extracted which can result in a uterine tear, and would be unlikely to make her **pale and tachycardic**

Question 32

Actinomycosis

Answer 32

* **Actinomycosis** is a specific disease characterized by a classical rarefying mandibular osteomyelitis and commonly known as “lumpy jaw” in cattle. It is caused by a Gram positive, branching filamentous organism—**Actinomyces bovis** * caused by the bacteria Actinomyces bovis, which is a normal inhabitant of the bovine mouth. * Actinomycosis is a chronic bacterial disease and is more common in cattle than in goats and sheep. * The bacteria enter through cuts and abrasions (i.e. due to teeth eruptions or coarse feed) and migrate to the bone, leading to osteomyeltitis (inflammation and infection of the bony tissues). * The mandible is affected more commonly than the maxilla. The defining feature of actinomycosis is the presence of a non-painful swelling under the jaw. * This swelling can rupture and drain pus-type, smelly fluid which contaminates the environment.

Question 33

Most common pathogens involved with Bovine Respiratory Disease (BRD)? (4) calves with BRD? (3)

Answer 33

* There are many types of infectious agents involved. * The most common viruses involved with BRD include **Bovine Viral Diarrhea (BVD)**, **Infectious Bovine Rhinotracheitis (IBR)**, **Bovine Respiratory Synctial Virus (BRSV)**, and **Parainfluenza Type-3 Virus (PI-3)**. * Exposure to these viruses can cause severe damage to the respiratory tract of calves creating opportunities for bacteria to then settle in the lungs. * Fortunately, many of these agents can be prevented through vaccination programs. * The most common bacteria found in the lungs of calves with BRD include **Mannheimia haemolytica and Pasteurella multocida**. * **Haemophilus somnus may also be involved in cases of pneumonia** and can cause severe damage to the heart muscles.

Question 34

Johnes Disease

Answer 34

* Johne's disease is a chronic enteritis of ruminants caused by **Mycobacterium avium subspecies paratuberculosis (MAP)​**. * This bacteria embeds itself in the wall of the lower part of the small intestine known as the ileum. As an immune response, infected tissues attempt to regenerate healthy tissue which leads to visible thickening of the intestines. * The main signs in cattle are progressive weight loss and chronic diarrhoea

Question 35

Fusobacterium Necrophorum

Answer 35

* Fusobacterium necrophorum, a **gram-negative, nonsporeforming anaerobe**, is a normal inhabitant of the alimentary, respiratory, and genital tract of animals. * The organism is an opportunistic pathogen and a primary causative agent of liver abscesses, an economically important disease of grain-fed cattle

Question 36

FAMACHA Scoring

Answer 36

* FAMACHA scoring identifies anemia in small ruminants, the main symptom of barber's pole worm infestation. Faffa Malan developed a five color FAMACHA scoring chart that corresponds to a sheep or goat's bottom eyelid color. * Pale pink to white indicates anemia; the animal should be dewormed. * Robust red to salmon pink indicates the animal does not require deworming at time of test.

Question 37

Bovine Respiratory Syncytial Virus | (BRSV)

Answer 37

* **BRSV** was named for its characteristic cytopathic effect, the formation in infected tissue of **syncytial cells, giant multinuclear** cells formed by the fusion of several cells. BRSV has a predilection for the lower respiratory tract, where it can cause varying degrees of pneumonia by itself. * The key to being able to make this your top differential is noting that the calf has a **"honking" cough**, dyspnea, and tachypnea, that the calf is not septic * Pulmonary lesions include severe edema and emphysema. * Treatment is usually supportive and antibiotics are given to protect from secondary bacterial infection. * **Mannheimia hemolytica** is the main culprit in shipping fever, and **Haemophilus pleuropneumoniae** is an occasional cause of shipping fever in cattle. * **Pasteurella multocida** can be a secondary invader in any bovine pneumonia. P multocida also causes the most economic loss in swine with atrophic rhinitis.

Question 38

Pathogens of **"Shipping Fever"**

Answer 38

* ***Mannheimia haemolytica*** * ***Pasteurella multocida*** * various other bacteria and viruses Normally seen 10-30 days after transport sudden onset pyrexia, depressed appetite, increased respiratory rate, cough, increased respiratory noise, grunting can be found dead

Question 39

"Fog Fever" Acute Bovine Pulmonary Oedema and Emphysema Aytipcal Interstitial Pneumonia

Answer 39

**Non Infectious Disease - Associated with cattle grazing lush pastures!** * normally cattle over 2 years old * within 2 weeks of moving to lush autumn pastures * up to 50% of group affected * commonly fatal and difficult to treat/manage * **L-tryptophan** in grass gets converted to Indole Acetic Acid (IAA) in rumen which is converted to 3- methyl Indole (3MI) which is toxic to cattle lungs and they become fibrous

Question 40

Use of corticosteroids in pregnant cattle will.....

Answer 40

**cause abortion!!**

Question 41

Death Camas Toxicity

Answer 41

* highly toxic to cattle! * can be found in Montana * onion-like plant that cattle like to eat when lush in the spring * There is no treatment for death camas poisoning. The only way to avoid it is to minimize the concentration of the toxin in an animal’s diet. Livestock need to eat as little death camas, and as much grass, as possible

Question 42

Bacillary hemoglobinuria "red water disease"

Answer 42

* in cattle is an **acute, toxemic and highly fatal clostridial disease** exhibiting the clinical signs of **hemoglobinuria, fever and jaundice** * caused by germination of **Clostridium Novyi type D** spores in the liver after anaerobic damage by **migrating liver fluke larvae**. * ***_Cl. Novyi_* was formerly called *Cl. hemolyticum***. * Vaccination can prevent this disease.

Question 43

A young bull presents for a breeding soundness exam. What is the minimum recommended percentage normal morphology of sperm?

Answer 43

* **70% normal** * To be a satisfactory potential breeder, a bull must meet certain requirements including a normal physical exam, adequate scrotal circumference, sperm motility of at least 30% motile, and sperm morphology of at least 70% normal.

Question 44

What zoontoic infection is of concern from drinking unpasteurized cow's milk?

Answer 44

* **Mycobacterium bovis** * M. bovis is a very serious zoonosis transmitted to humans by raw milk and has been largely controlled by institutional measures and milk pasteurization in the United States * **Mycobacterium bovis (M. bovis)** is a slow-growing (16- to 20-hour generation time) aerobic bacterium and the causative agent of tuberculosis in cattle **(known as bovine TB)**. * It is related to **Mycobacterium tuberculosis, the bacterium which causes tuberculosis in humans**

Question 45

When is a chorioallantoic membrane slip first palpable in a heifer?

Answer 45

* **30-35 days** * This is known as the **membrane slip** and is considered a positive sign of pregnancy. * gestation of cows: **283 days**

Question 46

Lipofuscinosis

Answer 46

* lipofuscinosis is the general name for a family of at least eight genetically separate lysosomal storage diseases that result from excessive accumulation of lipopigments (lipofuscin) in the body's tissues. * These lipopigments are made up of fats and proteins * Lipofuscinosis is a storage disease that usually gives the liver a dark appearance

Question 47

What is the main lesion associated with **polioencephalomalacia** in cattle?

Answer 47

* **Necrosis of cortical gray matter** * A deficiency of thiamine is believed to be the main cause of the disease although others have been suggested, including excess intake of sulfur, lead, or sodium. Early recognition of the signs and treatment with thiamine is required to have success in treating the condition. **_Predisposing Factors:_** ● High concentrate diets (pastured animals can also develop disease) ● Feed with corn or sugar cane byproducts ● High grain intake may promote proliferation of thiaminase producing bacteria ● Rations with added sulfate to limit intake ● Ingestion of plant thiaminases or thiamine analogs

Question 48

Clinical Forms of Polioencephalomalacia | (acute vs. Subacute)

Answer 48

**_Acute Form_** ● Blindness ● Seizures ● Recumbency _Subacute Form_ ● **Initial signs** a. Decreased appetite b. Twitching (ears and face) c. Separation from the herd d. Hold head up in an elevated position e. Staggering, hypermetric gait **Later signs** a. Cortical blindness i. Absent menace, intact palpebral reflex and pupillary light response b. Dorsomedial strabismus c. Head pressing d. Teeth grinding e. Opisthotonus

Question 49

Post-mortem findings of polioencephalomalacia

Answer 49

a. Gyral flattening, brain swelling. **b. Brain tissue may fluoresce under UV light. -** accumulation of autofluorescent substances in **degenerating neurons** that seem to be localized to the **mitochondria** c. Cerebrocortical neuronal necrosis. d. Cortical spongiosis. e. Cavitation of cortical tissue. f. Multifocal vascular necrosis, hemorrhage, and necrosis in deep gray matter.

Question 50

Polioencephalomalacia

Answer 50

some causes: lead poisoning, lactic acidosis (grain overload - kill microbes req. to synthesize thiamine in the rumen), salt intoxication/water deprivation, bracken fern poisoning (produced thiamine destroying substance), sulfur intoxication, amprolium intoxication (competes for active sites wth thiamine)

Question 51

Neurological Symptoms in Cattle based on location of lesion Cerebral Cortex? Brain Stem? Cerebellum? Spinal Cord? Peripheral Nerves?

Answer 51

Question 52

more common Brainstem lesions in Cattle (5)

Answer 52

* Listeriosis is by far the most common * TEME = Thromboembolic meningoencephalitis

Question 53

Listeria

Answer 53

* **Listeriosis** is an infectious disease caused by a bacterium, **Listeria monocytogenes**. It is a zoonotic disease. * poorly fermented silage - often silage that results in having a high pH * cranial nerve deficits from microabscesses in the brainstem signs: * signs being asymmetrical (but can be symmetrical over time) * dull, depressed (due to inflammation of reticular activating formation) * see signs of CN's being affected (CN. V and VII most commonly affected)

Question 54

Diagnosis/Tx of Listeriosis | (8)

Answer 54

* **Mononuclear (mixed) cell pleocytosis** is an increased leucocyte count with a predominance of **lymphocytes and macrophages** * definitive Dx often made on necropsies * gram (+) bacteria that often respond well to these AB therapies * can also have dysphagia due to CN 9,10,12 being affected - also drool saliva a lot --\> need to correct acid/base derrangements (often **metabolic acidosis** bc as they drool, a lot of bicarbonate is lost and K+)

Question 55

common cerebral diseases in cattle | (8)

Answer 55

* TEME - caused by *histophilus somni* (a gram - bacillus) --\> can lead to pneumonia, polyarthritis, myocarditis, abortion, and meningoencephalitis

Question 56

Pathophysiology of CCN (5) (polioencephalomalacia) what might CSF analysis show?

Answer 56

PPP = pathway to produce energy via ATP in the brain and red cells sodium starts to move into the neuronal or RBC's as a result and water tends to follow --\> swelling see more of a change in mentation than with listeriosis (which is related to brainstem lesions)

Question 57

What neurological effect can BVDV cause?

Answer 57

* **cerebellar hypoplasia** * tend to see signs of cerebellar lesions (in calves infected in utero) = hypermetria, tremors

Question 58

Oleander toxicity

Answer 58

* All parts of the plant are toxic, including the dried leaves. Oleander contains a complex mixture of cardiac glycosides, mainly oleandrin, which are potent cardiac toxins * **oleander is cardiotoxic and causes arrhythmias**

Question 59

Hepatic Functions: metabolic? (2) Synthetic? (3) Excretory? (2)

Answer 59

* **phylloerythrin** : a rose-red photosensitizing porphyrin pigment formed as a degradation product of chlorophyll in the digestive tract of herbivorous animals and normally excreted especially in the bile but absorbed by the blood in pathological conditions ---\> leads to photosensitization in animals with hepatic damage

Question 60

Cases of Liver Damage that can e somewhat reversible | (a.k.a. not fibrotic or loss of blood supply)

Answer 60

Question 61

Signs of Liver Failure in Cattle

Answer 61

* Hepatoencephalopathy is less dramatic in cattle than it is in horses * photosensitization can be a more observable (peeling nose, watering eyes, general oedema of heads and eyes, affects depigmented areas)

Question 62

Common causes of Liver _Failure_ in Cattle (4)

Answer 62

**hepatic lipidosis**: often late in pregnancy or early lactation

Question 63

Lab Tests Indicating Liver Damage

Answer 63

* alk phos, GGT: comes from the bile ducts, so can reflect a chronic process with bile duct proliferation * whereas, hepatocellular enzymes may come from the hepatocytes themselves and indicate acute damage * clotting tests may also be abnormal

Question 64

Diagnosis of cause of Liver Disease

Answer 64

* Fecal sedimentation for flukes * US * **Liver biopsy is the best**: can be percutanous to determine cause of liver abnormality

Question 65

Pyrrolizidine Alkaloid Toxicity | (PA Toxicity)

Answer 65

* Ingested alkaloids are converted to pyrrolic esters by hepatic cytochrome p450 enzymes. These esters are alkylating agents, which react with cytosolic and nuclear proteins and nucleic acids * basically the cells age and then grow and grow as they don't die off (anitmitotic effects) - replaced by fibrosis when they die * lesions from intoxication consist of: megalocytosis (enlarged hepatocytes), hepatic fibrosis, biliary proliferation, and in some cases nodular regeneration of parenchyma * **senecio = RAGWORT** * **can be white fuzzy bits in alfalfa hay**

Question 66

Which species is most susceptible to PA Toxicity?? (then followed by which 4?)

Answer 66

* **PIGS particularly susceptible** * **chicken** * **trout** * **horses** * **cattle** * then sheeps/goats (150%-400% BW) - quite resistant!

Question 67

Hepatic Lipodosis

Answer 67

* Cattle less prone to pregnancy toxemia than other species (ponies, sheep, etc.) * can actually treat this condition sometimes with insulin as it decreases HSL (hormone sensitive lipase) which mobilizes fat tissue for use in gluconeogenensis

Question 68

What will you find on lab tests with hepatic lipidosis? (7)

Answer 68

* ketonuria * elevated free fatty acids * calcium often low * decreased glucose * decreased insulin * may have metabolic acidosis * may have elevated liver enzymes and neutrophilia

Question 69

Spastic Paresis "Elso heel"

Answer 69

* **Spastic paresis**, also known as Elso heel, affects cattle of many breeds (as well as pygmy goats) beginning from three weeks to 1 year of age. * It is believed to be caused by a combination of genetic and environmental factors which somehow cause over stimulation of the **gamma motor neurons of the spinal cord**. * A second disease, **inherited periodic spasticity** is a genetic disorder (probably single autosomal recessive) of most dairy breeds, and is seen rarely in beef breeds. * It first appears at 3 to 7 years of age and gradually worsens, when the animals develop marked muscular spasms of the hip and upper leg muscles.

Question 70

There is an appointment today for a work-up on a lame cow. "Playing the odds", **what digits are most likely to be involved, because these are the digits most often affected in dairy cattle?**

Answer 70

**LATERAL REAR DIGITS** * Over 80% of foot disease involving the digits involves the rear digits. * Additionally, approximately 85% of these involve the lateral aspect. * This is because they bear the majority of their rear limb weight on the lateral claw in the hind. * In the front, cattle put most of their weight on their medial claw

Question 71

A dairyman's favorite cow was bred by a new bull a few weeks ago and now his cow has pyometra. ## Footnote **What agent is most likely responsible for causing the cow's pyometra?**

Answer 71

* **Tritrichomonas foetus** * This organism is commonly associated with a post-coital pyometra in addition to causing early embryonic death. * Tritrichomonas foetus is an obligate parasite of the bovine reproductive tract causing a highly contagious venereal disease. * Infection of cows with T foetus most often leads to pregnancy loss, but typically a return to normal fertility.

Question 72

"Freshened" Cow

Answer 72

* Freshening occurs when milk production begins. * She's then a "wet" cow, as opposed to "dry," non-milk-producing animal

Question 73

Normal rectal temp of Cow/calf

Answer 73

* The rectal temperature reference range for an adult cow is 37.8-39.2°Celsius [100.0-102.5°Fahrenheit] * a little higher for a calf at 38.6-39.4°Celsius [101.5-103.5°Fahrenheit]

Question 74

Cow HR/RR

Answer 74

* 48-84 bpm * 10-30 breaths per minute

Question 75

"Milk Fever"

Answer 75

* **hypocalcemia!** * Milk fever is caused by a temporary blood calcium deficiency (also known as hypocalcaemia) which usually occurs around the time of calving and is one of the most common metabolic disorder in dairy cattle * may have teh resulting CS's: acute recumbency, hypothermia, difficulty hearing HR, neck turned toward thorax (pleurothotonus), "s" shaped curve of spine, rumen motility decrease, nose dry

Question 76

Actinomycosis "lumpy jaw"

Answer 76

* can result in a swollen lower jaw with an adjacent hard, relatively non-painful swelling * this condition results from the entry of the **normal rumen inhabitant Actinomyces bovis** into the bony mandible (usual site) or maxilla through a break in the mucous membranes or teeth. * It **may be arrested with therapy using sodium iodide,** **antimicrobials or even isoniazid off-label**, but the bony swelling seldom changes much, even if arrested. * These lumps are immovable hard swellings of the bones, usually at the level of the central molar teeth. * The swellings develop slowly and may take months to reach the size of a tennis ball * Infection with the bacterium Actinomyces bovis occasionally causes **osteomyelitis in the maxilla (cheek) and mandible (jaw) of adult cattle, most often beef cattle.** The organism may gain entry to the bone associated with permanent molar teeth eruption or traumatic buccal injury. * There is marked enlargement of the mandible and often one or more discharging sinuses. Pain and physical deformity cause problems with masticating fibrous food with consequent **rapid loss of milk yield and body condition.**

Question 77

What is the current recommendation for cows diagnosed with **Mycoplasma bovis mastitis?**

Answer 77

* **CULL** * Unfortunately, there is very poor response to treatment and since this is a very contagious organism, it is best to cull. * Other types of mastitis, such as Strep ag or coliform mastitis, may respond well to frequent milking, anti-inflammatories, and antibiotics. * It is the smallest living cell and anaerobic in nature. It does not contain any cell wall, and is therefore resistant to penicillin and other beta lactam antibiotics. * Mycoplasma bovis mainly affects cattle and has little effect on other production animals

Question 78

Which of the following is most appropriate for increasing the rumen pH of a cow with rumen acidosis to the optimum range?

Answer 78

* **Magnesium Oxide** * **which becomes Mg OH in the rumen** * You may also use magnesium hydroxide or magnesium carbonate

Question 79

You are in the process of auscultating a cow that presented for respiratory distress and you hear no breath sounds in the dorsal chest. What is your tentative diagnosis?

Answer 79

* **Pneumothorax** * Since there is free air in the chest, the lung has lost its vacuum and is collapsed. The free air moves dorsally and you are unable to hear any lung sounds. * could be a pulmonary contusion, but given the location, pneumothorax is more likely * whereas, aspiration pneumonia would be usually cranioventral in location

Question 80

A herd of cattle present for an acute onset of a mild cough. Many of the cattle subsequently die and the others have improved over the course of several days. The cattle had a history of being moved to a lush pasture. Necropsy findings showed acute interstitial pneumonia and air filled bullae. ## Footnote **What is the likely chemical responsible for this disease?**

Answer 80

* **3-Methylindole** * Cattle that are moved to lush forage that is high in tryptophan metabolize the tryptophan to 3-methylindole in the rumen. * The 3-MI is toxic to the lung, resulting in **acute interstitial pneumonia and emphysema**. * This syndrome is known as acute bovine pulmonary edema and emphysema (ABPEE), fog fever or grunts

Question 81

Which of the following is the most common cause of pericarditis in cattle as shown in the photograph?

Answer 81

* **Traumatic reticuloperitonitis (hardware disease)** * Cattle ingest wires which then perforate the reticulum and migrate into the pericardium and cause an infection. * In small ruminants, Clostridium perfringens will cause pericarditis. * In swine, pericarditis may be caused by haemophilus, streptococcus, and Stephanurus edentatus

Question 82

Hydroallantois

Answer 82

* **Hydrops allantois (hydroallantois)** is a disorder of the placenta and the prognosis for life of the fetus and fertility of the cow is poor * due to a defective placenta (the chorio-allantois). The fetus is normal. The condition is characterized by a **rapid accumulation of watery, clear fluid (100-200L), usually in the last trimester** * The cow develops a rounded appearance to the abdomen and it is usually not possible to palpate the fetus or placentomes. * The cow often becomes sick with anorexia, decreased rumen motility, dehydration and weakness. She may go down or rupture the prepubic tendon. * The prognosis for the **fetus is guarded and even with treatment, the cow will likely be infertile**. * Induction of parturition or C-section are treatment options but the majority of calves are not viable and the dam rarely has normal colostrum. * If the pregnancy is terminated, it is unlikely that the cow will have a productive milk cycle. * Usually salvage for slaughter is the preferred option unless the fetus is considered valuable and the cow is near term

Question 83

Hydramnios | (Hydrops Amnion)

Answer 83

* **Hydramnios** is a disorder of the fetus, and the placenta itself is normal. * The condition is typically characterized by gradual accumulation of thick viscous fluid during the later part of gestation. * The cow develops a pear shaped caudal view. * The fetus and placentomes are usually palpable and the cow is usually clinically well. * Pregnancy usually goes to term and a small, deformed fetus is delivered. The cow has a fair to good prognosis for life and fertility. The cow may be induced or allowed to go to term depending on her condition

Question 84

Signs of heart Failure in Cattle? Common Causes?

Answer 84

* tachycardia, edema, enlarged/dilated jugular veins * The main causes are pericarditis, endocarditis, heart base lymphoma, and hereditary muscle disorders (+gossypol toxicity in calves) * may get muffled splashy heart sounds with traumatic reticulopericarditis (metallic foreign body that pierces the reticulum)

Question 85

Ringworm | (Dermatomycosis)

Answer 85

* Ringworm is a dermatomycosis that tends to occur most commonly in housed, crowded calves in winter when there is little UV light present. * The most common dermatophyte in cattle tends to be **Tricophyton verrucosum**, with **T. mentagrophytes** second most common. * Therapy includes such topical treatments as captan, diluted bleach, lime sulfur, or miconazol shampoos. * Systemic treatment is rarely needed.

Question 86

Infectious Bovine Keratoconjunctivitis (IBK) Which pathogen is involved?

Answer 86

* Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, New Forest eye or blight, is a veterinary infection of cattle caused by Moraxella bovis, a Gram-negative, β-haemolytic, aerobic, rod-shaped bacterium. It is spread by direct contact or by flies serving as vectors * most common bacteria causing this is Moraxella bovis, although other organisms including Neisseria species and Moraxella ovis can also induce similar lesions in cattle. * Also, **IBR and mycoplasma** seem to be risk factors that may increase the risk of developing IBK

Question 87

Calf Diptheria

Answer 87

* This is a disease associated with **Fusobacterium necrophorum**, which is a strict anaerobic bacteria found everywhere in the environment. * The disease is usually trasmitted by oral ingestion of the bacteria. * Also called necrotic laryngitis, or laryngeal necrobacillosis, this mainly feedlot condition strikes randomly but can result in death or a permanently misshapen larynx. * The causes appear to be Histophilus somni and Fusobacterium necrophorum * There are two forms of calf diptheria; **oral (less than 3 months old) and laryngeal (older calves)** * **Swelling of the rostral cheek and salivation** are the main clinical signs * Upon physical examination, there may be a foul smell emitting from the mouth and deep necrotic lesions may be found on the cheek or tongue * **If the larynx or pharynx are involved**, swelling may lead to dyspnoea and the presence of pneumonia. These animals will also be pyrexic. They usually die fairly quickly as exudate may block the airways.

Question 88

Lupine alkaloid Toxicity

Answer 88

* More common than direct toxicity, some **lupine alkaloids** produce birth defects in cattle if eaten during certain gestational times. * Cows eating lupine during early gestation often give birth to calves with cleft palates, crooked legs and distorted/malformed spines. --\> **"crooked calf syndrome"** * Such deformed calves generally have to be euthanized. Epidemic outbreaks of such birth defects can have high morbidity resulting in enormous animal and economic losses.

Question 89

What is the most common respiratory disease of barn raised dairy calves 1-6 months of age in the United States?

Answer 89

* **ENZOOTIC PNEUMONIA** * This disease is multifactorial but is mainly a result of poor housing and environment (poor sanitation and ventilation). * Calves with enzootic pneumonia will have cranioventral consolidation and many times they concurrently have coccidiosis (Eimeria bovis). * This disease can be economically devastating because calves gain weight more slowly (some may die) and later in life calving is delayed * ***Pasteurella multocida*** is the most common cause of enzootic pneumonia, however ammonia, carbon dioxide, hydrogen sulfide, Mycoplasma, Trueperella pyogenes, BVD, BRSV, and PI3, have all been known to contribute to the disease

Question 90

Epizootic Bovine Abortion "Foothill Abortion"

Answer 90

* **Foothill abortion**, also called Epizootic Bovine Abortion (EBA), affects cattle in **California, Nevada and Oregon**. * It is caused by a **bacterium that is vectored by the Pajaroella tick (*Ornithodoros coriaceus*)**. These ticks occur in areas with sage, bitter brush, pinyon pines, junipers, and oaks * **Abortion occurs more than 3 to 4 months after exposure,** so **keeping pregnant heifers out of the foothills until they are 6 months pregnant** means they calve before fetal lesions occur. * Raising heifers in the foothills until breeding does provide premunition immunity. * Also, the rancher should keep these heifers that abort, as they will **now be immune to EBA**. * Tick control is very difficult on cattle running in the hills, but the ticks do not inhabit irrigated pastures (they live in the dry ground duff of needles and leaves), so bred heifers can be kept in irrigated pastures for months 1-6 of pregnancy

Question 91

Pyelonephritis

Answer 91

* **Pyelonephritis** occurs most commonly in post-partum cows when bacteria enter via the urethra due to a post-partum uterine infection and vaginal damage at calving. * The most common organisms found are coliforms or **Corynebacterium renale**. * The resultant ascending infection causes renal swelling and pain (grinding teeth, swishing tail, repeatedly up and down), fever, and loss of appetite.

Question 92

Infectious Bovine Rhinotracheitis (IBR)

Answer 92

* **Infectious Bovine Rhinotracheitis (IBR)** is a highly contagious, infectious respiratory disease that is caused by **Bovine Herpesvirus-1 (BHV-1)**. It can affect young and older cattle. * Diagnosis can be made from viral isolation of **nasal or ocular swabs** from live animals or from bronchial lymph nodes or tracheal tissue in deceased animals. Serology submitted 2-3 weeks apart can also confirm a diagnosis of IBR. * The different strains of IBR tend to produce different syndromes * The disease is characterised by **inflammation of the upper respiratory tract**. * Bovine herpes virus 1 (BHV 1) also causes infectious **pustular vulvovaginitis** in the female, and infectious balanoposthitis in the male and can cause abortions and foetal deformities. * IBR is endemic in the UK with around 40% of cattle having been exposed to the virus in the past. Infected cattle develop a latent infection once recovered from the initial infection and despite appearing clinically normal may suffer **recrudescence of disease when under stress**

Question 93

SCC anaylsis and cut-offs

Answer 93

* Many studies suggest that cows with SCC of less than 200,000 are not likely to be infected with major mastitis pathogens, but cows **with SCC above 300,000 are probably infected** (Smith, 1996). * Herds with bulk tank SCC above 200,000 have varying degrees of subclinical mastitis. **At 500,000 SCC, approximately 16% of the mammary quarters may be infected, resulting in a 6% reduction in milk production compared to a SCC of 200,000**

Question 94

Which organism is most commonly isolated in **pituitary abscesses of ruminants**?

Answer 94

* **Trueperella pyogenes (formerly Arcanobacterium pyogenes)** * T. pyrogenes is the main causative agent for brain abscess syndrone in white-tailed deer. * It also commonly causes abscesses in other parts of the body in deer, moose, pronghorn, and wild sheep. * While it is rare, humans can contract T. pyogenes if they come in contact with infected deer, though the bacteria is often misidentified

Question 95

Paradoxic aciduria

Answer 95

* Normally the kidney **excretes some potassium** because of the need to maintain an equal number of anions and cations in the urine. But when there is insufficient potassium available, in order to reabsorb sodium to maintain blood pressure, hydrogen ions are excreted rather than potassium. * This results in **acidic urine at the same time as metabolic alkalosis**, a condition known as **paradoxic aciduria.**

Question 96

When is a fetus susceptible to becoming a BVDV PI calf?

Answer 96

* A **susceptible non-immune cow** carrying a fetus between **60 and 150 days gestation**, if infected by a **non-cytopathic biotype of BVD**, can pass the virus to her fetus which may become persistently infected. * This calf can spread virus to herd mates for the duration of its life * **normal gestation of cow: 283 days**

Question 97

Causative Agents of Pink Eye in Cattle

Answer 97

***Moraxella bovis.*** **(infectious Bovine Keratoconjunctivitis)** ● Pathogenic strains have various types of pili and a cytotoxin. a. **Other organisms can cause pinkeye too:** i. Chlamydia ii. Infectious bovine rhinotracheitis (bovine herpesvirus-1) iii. Mycoplasma iv. Neisseria catarrhalis ● These can make the disease more severe or make it easier for M. bovis to cause secondary infection. a. CF pigmentation around eye results in UV damage and subsequent inflammation thus sensitizing eye to infection. b. Hereford cattle now bred for pigment around eyes because of pinkeye and squamous cell carcinomas **See higher incidence in summer and fall due to increased flies, UV light, and pollen production. - Transmission** **● Younger cattle more commonly affected.​**

Question 98

Treatment and Prevention of IBK

Answer 98

* Small opaque region in center of cornea progresses to **deep central ulceration** * a. Perforation of corneal ulcer is uncommon. * Antibiotics * a. **Oxytetracycline (LA-200) systematically** * b. Labeled for treatment of IBK * c. Ceftiofur (Naxcel) SQ - 3rd generation cephalosporin * d. Penicillin subconjunctivally * e. Florfenicol IM * f. Tulathromycin SQ ● Surgical intervention a. Can perform third eyelid flap or tarsorrhaphy. Eliminate environmental factors a. Protect eyes from UV light by using glue on eye patch b. Control fly population with face rubbers and ear tags c. Grass, weed, and brush control to minimize mechanical irritation d. Eliminate overhead feeding ● Prevent other predisposing diseases a. Vaccinate for BVD and IBR b. Isolate infected animals ● Vaccination for IBK a. Mixed results. If both humoral IgG and secretory IgA directed at M. bovis antigens are present, these appear to be protective. b. Not consistently effective therefore not yet in widespread use.

Question 99

Diseases caused by ***Fusobacterium necrophorum***

Answer 99

* Necrotic Laryngitis * abscesses * infectious footrot calves may present septic - gram (-) bacteria and therefore produces enterotoxin Treatment (gram - anaerobe): Procaine Penicillin G, Oxytetracycline, Cephalosporins Pain medication: Flunixin meglumine

Question 100

Type I Vagus Indigestion

Answer 100

* **Type I vagus indigestion** is **failure of eructation**, and results in free gas bloat and ruminal distention. * **Inflammatory lesions, chronic pneumonia or a localized peritonitis** following hardware disease of the vagus nerve cranial to the cardia have been implicated. * Mechanical factors not related to vagus nerve damage that cause esophageal obstruction may also cause failure of eructation.

Question 101

Type II Vagal Indigestion

Answer 101

* **Type II vagal indigestion**, more correctly termed failure of omasal transport, develops as a result of any condition that prevents ingesta from passing through the omasal canal into the abomasum. * Adhesions and abscesses (reticular or single liver abscesses) are the most common cause of failure of omasal transport and are usually located on the right or medial wall of the reticulum near the route of the vagus nerve. * Reticular abscesses and adhesions are almost invariably the result of **traumatic reticuloperitonitis**. * Mechanical obstruction of the omasal canal by ingested material (eg, plastic bags, rope, placenta) or masses (eg, lymphosarcoma, squamous cell carcinoma, granulomas, or papillomas) can also cause chronic ruminoreticular distention due to failure of omasal transport.

Question 102

Bovine Respiratory Syncytial Virus

Answer 102

* **Bovine respiratory syncytial virus (RSV)** is an important cause of pneumonia in calves. * The disease occurs as annual winter outbreaks in housed calves during the first 6 months of life

Question 103

3 most common causes of colic

Answer 103

* intussusception * cecal dilation (with or without torsion) * abomasal volvulus

Question 104

Possible causes of **ulcerative necrotic interdigital lesions** in cows?

Answer 104

* **FMD** * **BVD** * **Interdigital necrobacillosis** * **Malignant catarrhal fever**

Question 105

In what case would you expect a CSF tap from a cow exhibiting neurological signs to have **mononuclear pleocytosis**? What about **neutrophilic pleocytosis**?

Answer 105

* mononuclear = ***Listeria spp.*** * neutrophilic = **Thromboembolic Meningoencephalitis (TEME)** * with Listeria, you will often observe CNS signs, an increased number of monocytes and macrophages. Also remember that Listeria is usually contracted from ingesting silage that has been stored at a pH \> 5.0.

Question 106

Cor Pulmonale

Answer 106

* **Cor pulmonale** is defined as an alteration in the structure and function of the right ventricle (RV) of the heart caused by a primary disorder of the respiratory system. * **Pulmonary hypertension** is often the common link between lung dysfunction and the heart in cor pulmonale

Question 107

Adductor Muscles of Pelvic Limb

Answer 107

* Adductor brevis * Aductor longus * gracillis * pectineus

Question 108

Brisket Disease

Answer 108

* **Brisket disease** occurs as a result of lack of oxygen at high altitude. * As the syndrome progresses, subacute edema develops in the brisket region. Marked **distention and pulsation of the jugular veins are usually present.** * High mountain disease (brisket disease) is **right heart failure due to hypoxic pulmonary hypertension in cattle residing at high altitudes.** * Hypoxia is the most potent stimulus for pulmonary hypertension, and the hypoxia of high altitude (\>7,000 ft) is a well known cause. * Can measure being prone to it at about **6000ft**

Question 109

"Cancer Eye"

Answer 109

* **ocular squamous cell carcinoma** (also known as "cancer eye") which is one of the most common neoplasms of cattle and causes significant economic loss due to shortened productive life and condemnation at slaughter. * The etiology is multifactorial but is believed to have a heritable component as well as association with sunlight, eyelid pigmentation, and nutrition. * The diagnosis can be made from the clinical presentation and fine needle aspirate showing a cluster of **epithelial cells with anisocytosis and basophilic, vacuolated cytoplasm**.

Question 110

"Preconditioning" calves

Answer 110

* Preconditioning involves being sure that calves are **weaned several weeks before** entering the feedlot, **vaccinated against infectious bovine rhinotracheitis (IBR), bovine viral diarrhea (BVD), Parainfluenza-3 (PI3), and Clostridial diseases.** * They should be dewormed, and dehorned and castrated if not already done. Ideally, the calves should also have learned to eat from a bunk and drink from a trough before entering the feedlot. Then, when the calves are mixed with calves from other ranches, they are less likely to succumb to respiratory disorders.

Question 111

What is the average duration of estrus in a cow?

Answer 111

* **8-18 hours** * receptivity may last up to 50 hours

Question 112

What does eosophageal dysfunction in a calf lead to?

Answer 112

**Rumen Acidosis** * Esophageal groove dysfunction is one of the major causes of **ruminal bloat**. * This condition is **fatal in new born calves if it is not treated early.** * In healthy, suckling calves, milk should bypass the forestomach (rumen and reticulum) and enter into the abomasum where **enzymatic digestion of milk proteins takes place**. * the esophageal groove (also known as reticular groove) is a specialized part of the ruminant stomach that closes in response to drinking milk, directing it directly to the abomasum. **When dysfunctional, milk goes to the rumen where it is fermented by rumen microbes and converted to volatile fatty acids and lactic acid. --\>** For this reason, this phenomenon is sometimes referred to as rumen drinking. * might develop **white, puddy-like feces**

Question 113

Poloxalene

Answer 113

* Poloxalene is a **non-ionic surfactant** that **lowers the surface tension of the frothy mass so the bubble film is weakened** * Petitioned for treatment of l**egume (alfalfa, clover) bloat (ruminal tympany) in cattle**. * It is also used as a surfactant and dispersant in pesticide formulations

Question 114

How do you diagnose the presence of Streptococcus agalactiae?

Answer 114

**Perform a CAMP reaction** * This organism usually causes subclinical mastitis, but sometimes you may see high somatic cell counts and clinical signs with this organism. * Perform a **CAMP reaction to diagnose this organism.** * That is when you plate S. aureus and S. agalactiae and you see them act together to **lyse red blood cells.** * This creates a clearing on your culture plate.

Question 115

WInter Dysentery

Answer 115

* **Winter dysentery** is an epidemic disorder of housed cattle, usually occurring in cold months and affecting **10-90% of adult cows**. * If fever occurs at all, it usually precedes the diarrhea phase (**brownish fetid liquid feces full of bubble**s) * The disease is thought to be caused by **coronavirus**, and lesions involve the colon. In typical outbreaks, the disease runs its course in weeks and the herd becomes immune and recovers, although milk production may not recover to previous levels.

Question 116

Mycoplasma bovis in young calves

Answer 116

* may show **vestibular signs and facial n. paralysis!** * M. bovis may be spread to young calves via milk. * In very young dairy calves it can cause **otitis media with aural discharge, head tilt, nystagmus, ataxia, and even facial nerve paralysis.** It also causes respiratory disease and can cause arthritis and tenosynovitis in **older calves**. * Mastitis, abortion and other signs can also be caused by M. bovis.

Question 117

Sodium Iodide

Answer 117

* As an aid in the treatment of **actinomycosis and actinobacillosis** in cattle and as an expectorant in mild respiratory disease of cattle, horses and sheep * Also would want to change feed to avoid lesions allowing access through mucosa - Upon injury, the normal inhabitant Actinobacillus lignieresii invades the soft tissues and causes the characteristic woody tongue granulomatous inflammation.

Question 118

What are 2 disease that can make cattle become more aggressive/wild?

Answer 118

* **Rabies** (but usually see the paralytic type in cattel rather than aggression) * **anaplasmosis** (check MM)

Question 119

Several 6-month old calves in a herd have been losing weight and showing signs of diarrhea. As part of your work up to diagnose the problem in the herd, you perform a McMaster fecal egg count. ## Footnote **Which of the following is an appropriate minimum egg count at which you should plan to deworm the calves to promote weight gain?**

Answer 119

**300 eggs per gram of feces** * Once you see an egg count between 300-400 per gram, with or without compatible clinical signs, you should consider deworming. * That is the level at which weight gains in growing calves will begin to be affected.

Question 120

What causes grass tetany in cattle?

Answer 120

**Hypomagnesemia** * **Hypomagnesemic tetany (grass tetany)** - It usually occurs in cold or cool weather in pastured lactating beef or dairy cows. * **Lush pastures** that are high in potassium and nitrogen and low in magnesium and sodium are most often involved. * CS's: eyelids are fluttering, there is nystagmus, and champing of the jaws, on side and paddling, death

Question 121

Salmonella Dublin in Calves

Answer 121

* S. dublin tends to cause septicemia in dairy calves **4 to 8 weeks of age** * The organism can be transmitted by carrier cows to neonates at birth or via their milk. * **Diarrhea** is a common consequence of Salmonella infections. However, the common presenting sign of S. Dublin infections is **respiratory disease** in calves 2 to 12 weeks of age. * The most effective control measures are to cull carriers and vaccinate calves using a modified live S. dublin vaccine.

Question 122

A dairyman's favorite cow was bred by a new bull a few weeks ago and now his cow has pyometra. ## Footnote **What agent is most likely responsible for causing the cow's pyometra?**

Answer 122

**Tritrichomonas foetus** This organism is commonly associated with a post-coital pyometra in addition to causing early embryonic death

Question 123

Spastic Paresis | (aka Elso heel)

Answer 123

* This is a **hereditary disease** which produces a continuous stiffness of the hocks. * Spastic paresis or Elso-heel is a **progressive neuromuscular disease** which affects the hind limb in young cattle * It is believed to be caused by a combination of genetic and environmental factors which somehow cause **over stimulation of the gamma motor neurons of the spinal cord** * There could be bilateral or unilateral involvement. It is a recessive disease; therefore, affected animals should not be bred. * A second disease, **inherited periodic spasticity is a genetic disorder** (probably **single autosomal recessive**) of most dairy breeds, and is seen rarely in beef breeds. It first appears at **3 to 7 years of age** and gradually worsens, when the animals develop marked muscular spasms of the hip and upper leg muscles. * Treatment involves a **tibial neurectomy or gastrocnemius tenectomy.**

Question 124

Location of ping for Rumen

Answer 124

* you hear a monotone "boink" on the left side, dorsally, approximately **between rib spaces 9-13 and extending to the hip** * where as an LDA would be only behind the last rib and not extend to the hip

Question 125

What are the 3 genera of blood sucking cattle lice?

Answer 125

The three genera of blood sucking cattle lice are Solenopotes, Linognathus, and Hematopinus

Question 126

2 most common pathogens of pyelonephritis in post-partum dam

Answer 126

* Pyelonephritis occurs most commonly in post-partum cows when bacteria enter via the urethra due to a post-partum uterine infection and vaginal damage at calving. * The most common organisms found are **coliforms** or **Corynebacterium renale**. * The resultant ascending infection causes renal swelling and pain (grinding teeth, swishing tail, repeatedly up and down), fever, and loss of appetite.

Question 127

A "honking" cough can be indicative of which infection?

Answer 127

* **Bovine respiratory syncytial virus** * often see mucopurulent nasal discharge as well * white plaques are noticed on the conjunctiva and nasal epithelium

Question 128

Answer 128

**STRUVITE** * Struvite is composed of magnesium ammonium phosphate. The alkaline urine in cattle along with high dietary phosphate and magnesium levels favors formation of **struvite stones.** * Feedlot animals can also develop apatite stones composed of calcium phosphate

Question 129

5 types of Bovine Papilloma Virus (BPV)

Answer 129

There are at least **five strains of papillomavirus**, **each of which has a specific predilection site on the cow**. * **BPV type I** causes wart like lesion on the nose, teats or penis and affect young cattle and will usually regress over time. * **BPV type II** causes warts all over the skin of the head and neck of young cattle and will usually regress over time. * **BPV type III** causes atypical warts which are smooth and white in appearance and occur mainly on the teats and udders of older cows. * **BPV type IV** causes papillomas in gut, especially the rumen, and bladder, as well as lesions on the eye. This particular systemic form can be refered to as **papillomatosis.** The papillomas caused by this strain can undergo malignant transformation to alimentary carcinomas, however, this transformation is usually concurrent with grazing bracken (co-carcinogen) and ingesting quercetin (immunosuppressant). In Hereford cattle, the **papilloma can transform to a squamous cell carcinoma** of the eye, where **UV light acts as the co-carcinogen**. * **BPV type V** causes tiny warts on the teat. Infection is spread by direct contact from cow to cow or by indirect contact from fomites. With most strains, calves are most commonly affected.

Question 130

Malignant catarrhal fever (MCF)

Answer 130

* **Malignant catarrhal fever (MCF)** in North America is caused by s**heep-associated ovine herpesvirus-2**. * **A very high percentage of sheep and goats in North America are infected with OHV-2** and can transmit the virus to susceptible cattle, bison, deer, and other related species, even if only in close proximity and not in direct contact. * The virus causes **lymphocytic vasculitis** and can be fatal.

Question 131

Mucosal disease, or alternatively, chronic Bovine Virus Diarrhea (BVD) occurs in cattle when?

Answer 131

* A **5-month old calf** which was persistently infected as a fetus with a **non cytopathic (nonCPE)** biotype of BVD virus is superinfected with a **cytopathic (CPE) biotype of BVD due to rearranging of the parent non-CPE viral RNA**

Question 132

Would you see hemoglobinuria with anaplasmosis in cattle?

Answer 132

* **NO**

Question 133

When is a chorioallantoic membrane slip first palpable in a heifer?

Answer 133

The correct answer is **30-35 days**. This is known as the **membrane slip** and is considered a positive sign of pregnancy

Question 134

Treatment for Endometritis?

Answer 134

* **Systemic ceftiofur may be best** * Intrauterine penicillin (after 30 days) or tetracycline or ceftiofur can be beneficial. * **The negative impact can be antibiotic residues in milk** (up to 80 hours for penicillin and 96 hours for tetracycline in milk) and in tissues ( up to 12 days for penicillin), so some prefer to use dilute povidone iodine, or uterine lavage with saline. * **Systemic ceftiofur achieves adequate intrauterine levels and is thus the safest and best of the options** * Prostaglandins can also be given to "short cycle" the cow which will aid in treating the endometritis. * The other drugs listed are not legal for use in the USA, and could cause harmful residues to appear in milk..

Question 135

Which country is Anaplasma free?

Answer 135

**CANADA** * Anaplasma can often be treated successfully with a single injection of long acting tetracycline (20 mg/kg) * When the PCV is below 12%, a blood transfusion may also be needed

Question 136

**Prey-Predator** Cycles of ***Sarcocystis spp***.

Answer 136

* ***Sarcocystis spp*** normally develop in two-host cycles consisting of an intermediate host (prey) and the final host (predator). * Species-specific prey-predator life cycles have been demonstrated for: * cattle-dog (**S cruzi**) * cattle-cat (**S hirsuta**) * cattle-human (**S hominis**) * sheep-dog (**S capracanis, S hircicanis**) * sheep-cat (**S gigantea, S medusiformis**) * goat-dog (**S capracanis, S hircicanis**) * goat-cat (**S moulei**) * pig-dog (**S meischeriana**) * pig-human (**S suihominis**) * pig-cat (**S porcifelis**) * horse-dog (**S fayeri**) * llama-dog (**S aucheniae**) * pigeon-hawk (**S calchasi**)

Question 137

Akabane Disease

Answer 137

* **Arthropod-borne disease** * Akabane disease is an arthropod-borne viral disease that can affect cattle, sheep and goats. * In the predominant syndrome, inapparent infections in adults can lead months later to abortions, stillbirths and congenital defects in newborns. * **Most affected neonates die or must be euthanized** * **may see** fetal brain lesions such as **hydranencephaly or hydrocephalus in fetal calves​**

Question 138

What amount of colostrum should be ingested by calves after birth?

Answer 138

* **Immunoglobulin G** in the total amount of 150 to 200 grams per dairy calf seems to be optimal. * If average dairy cow colostrum contains 35 mg/mL of IgG1, this requires that **at least 4 liters of colostrum be ingested.**

Question 139

**Infectious bovine rhinotracheitis ophthalmic lesions** are caused by which virus?

Answer 139

* **Bovine Herpes Virus 1** * The virus infects the trigeminal ganglia and becomes latent. * When an animal is immunosuppressed, the virus replicates and causes disease. * The **ocular signs of the disease** include **serous to mucopurulent conjunctivitis** * **Herpes II** causes bovine **ulcerative mammilitis**. * **Herpes III** is the alcelaphine herpes virus (**African malignant catarrhal fever**)

Question 140

Mucosal Disease

Answer 140

* Mucosal disease is an uncommon but highly fatal form of BVD occurring in persistently infected cattle and can have an acute or chronic presentation. * Mucosal disease is induced when persistently infected cattle become **superinfected with cytopathic BVDV.** * **ex:** A 5-month old calf which was persistently infected as a fetus with a non cytopathic (nonCPE) biotype of BVD virus is superinfected with a cytopathic (CPE) biotype of BVD due to rearranging of the parent non-CPE viral RNA

Question 141

Why might you see anemia associated with copper deficiency?

Answer 141

* **Copper is essential for absorbing iron from the gut.** When copper levels are low, the body may absorb less iron. * This can cause **iron deficiency anemia**, a condition in which the body is unable to carry enough oxygen to its tissues.

Question 142

What is the typical TPN measure for a calf? (parenteral nutrition)

Answer 142

A typical TPN mixture for a calf this size would be * 1L of 10% **amino acids** * 1L of 50% **glucose** * 500 ml of 10% **lipids** * per day

Question 143

4 Clinical Types of Abomasal Ulcers

Answer 143

Question 144

Clinical Signs of Bleeding Ulcers | (5)

Answer 144

Question 145

Ways to alter gastric/abomasal secretion (4)

Answer 145

Question 146

Treatment of Abomasal Ulcers | (6)

Answer 146

Question 147

What disease in cattle and sheep is closely related to African Horse Sickness?

Answer 147

* **BLUETONGUE** * **(less virulent in endemic areas like California)** * strains of different serotypes vary greatly in terms of pathogenicity!

Question 148

Bluetongue as a teratogen in cattle

Answer 148

Question 149

Calf D+ before 6 days of age?

Answer 149

* could begin to think it may be the result of sepsis * remember volume of colostrum is more important than quality these days! - make sure they get 4L of colostrum to ensure **adequate intake of immunoglobulins**! * discard milk that may have antibiotics in it!

Question 150

Flies, cats, dogs, mice, pigeons and Salmonella transfer

Answer 150

Question 151

How long do lactations usually last in the cow?

Answer 151

lactations usually last around **305 days** and then the cows are **dried off for 60 days.**

Question 152

What is the first line of treatment for ventricular tachycardia in cattle?

Answer 152

* **LIDOCAINE** * If there is no response with lidocaine then propranolol and quinidine may be used.

Question 153

Possible causes of footrot in cattle?

Answer 153

* **Trueperella pyogenes** * **Prevotella melaninogenicus** is one of the main causes of footrot in cattle, along with **Fusobacterium necrophorum**.

Question 154

Electrical Alterans? Pulsus paradoxus?

Answer 154

* **Electrical alternans** is beat-to-beat variability of the QRS complex on electrocardiogram, often found in the setting of pericardial effusion. * **Pulsus paradoxus** is a drop of systolic blood pressure \>10 mmHg with inspiration and is associated with cardiac tamponade.

Question 155

Why would a cow with Salmonella exhibit severe pyrexia?

Answer 155

**Salmonella is gram negative and LPS would result from infections**