Equine

Question 1

What is entropion?

Answer 1

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.

Question 2

what is Ectropion?

Answer 2

where the eyelid everts out and can lead to exposure keratitis, but this is uncommon in horses.

Question 3

All aminoglycosides have the potential for causing tubular nephrosis. Which aminoglycoside is most nephrotoxic to horses?

Answer 3

Neomycin.

Question 4

On physical exam, you are able to extend the hock and flex the stifle simultaneously. What is your diagnosis?

Answer 4

peroneus tertius rupture. Damage to the peroneus tertius muscle disrupts the stay apparatus of the hind limb.

Question 5

most consistent with a diagnosis of chronic obstructive pulmonary disease in the horse?

Answer 5

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.

Question 6

By what mechanism does Parascaris equorum typically cause colic in foals?

Answer 6

Intestinal impaction

Question 7

Consumption of an ionophore in a horse classically results in ________.

Answer 7

myocardial toxicity. The main ionophore that results in toxicity is monensin. Horses are very susceptible to monensin toxicity.

Question 8

What is the definitive host of Dictyocaulus arnfeldi?

Answer 8

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.

Question 9

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

Answer 9

This horse most likely has aortic regurgitation due to degeneration of the aortic valve and should have no impact on performance

Question 10

typical presentation and findings of a horse with bog spavin which refers to swelling of the tibiotarsal joints. What is tx?

Answer 10

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

Question 11

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?

Answer 11

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.

Question 12

What is the most common way in which equine herpesvirus is transmitted?

Answer 12

Inhalation

Question 13

how long should it take for the placenta to be expelled after parturition ?

Answer 13

30min to 3hrs. it is considerate retained after 3-6hrs

Question 14

what is Theiler’s disease

Answer 14

(aka serum sickness or serum hepatitis). Theiler’s disease will cause and acute multifocal to diffuse hepatitis along with necrosis too.

Question 15

What is the proper site for thoracocentesis for pleural effusion removal in the horse if ultrasound is not available?

Answer 15

7th rib space at costochondral junction

Question 16

what is the Coggins test?? if a horse if positive for it, can we still give it corticosteroids ?

Answer 16

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

Question 17

what is Culicoides hypersensitivity?

Answer 17

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.

Question 18

what is Habronemiasis?

Answer 18

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.

Question 19

what is Haematobia

Answer 19

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.

Question 20

what is Onchocerca?

Answer 20

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.

Question 21

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

Answer 21

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.

Question 22

______ 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.

Answer 22

Arabian

Question 23

what is Guttural pouch tympany

Answer 23

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.

Question 24

what is the tx for equine cushing’s?

Answer 24

Pergolide -dopamine agonist to help decrease symptoms

Question 25

what is the most common ovarian tumor in horses that can lead to aggression ?

Answer 25

granulosa cell tumor

Question 26

buccal mucosal bleeding test is equivalent to ___ ____ _____

Answer 26

template bleeding time. It can determine functional ability of platelets to plug a minute wound

Question 27

most common gastril neoplasia in the horse vs the dog

Answer 27

-horse is SCC -dog is adnocarcinoma

Question 28

Strongyloides westeri is the _____. How do foals get them and what is the tx?

Answer 28

equine thread worm. Common in foals because it is transmitted in the mare’s milk. tx is ivermectin or oxibendazole

Question 29

Total body water is ___% of body weight. Extracellular fluid is approximately ___/__ of total body water

Answer 29

60% and 1/3

Question 30

What is the normal blood lactate in a healthy foal or horse?

Answer 30

2.5mmol/l

Question 31

dental formula for horses

Answer 31

2(I3/3 C1/1 P3-4/3 M3/3)

Question 32

How much sodium bicarbonate must be given to a 470kg horse that has a base deficit of 13 to completely correct this deficit?

Answer 32

0.4 x BW x Base Deficit

Question 33

Common clinical signs associated with fescue toxicosis in pregnant mares?

Answer 33

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.

Question 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)

Answer 34

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.

Question 35

What is the most common cause of blindness and cataract in horses?

Answer 35

Equine recurrent uveitis

Question 36

Which of these tests would be the best indicator of moldy sweet clover toxicity in a horse?

Answer 36

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).

Question 37

tx for a horse with “stringhalt”

Answer 37

lateral digital extensor tenectomy

Question 38

Bog Spavin vs Bone Spavin

Answer 38

Bone spavin: osteoarthritis of the distal intertarsal joint and/or tarsometatarsal joint

Bog spavin: synovial distention of the tarsocrural joint, does not cause lamness

Question 39

What is “ringbone” in horses and how do you treat it ?

Answer 39

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.

Question 40

African Horse Fever

• transmission
• Clinical Signs

Answer 40

• 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)

Question 41

The classic findings of renal failure include: ______, _______, _______, _______

Answer 41

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.

Question 42

what is the classical sign of ionophore toxicity in the horse

Answer 42

myocardial toxicity; usually happens when cow feeds gets mixed up with horse feed and horse eats monensin

Question 43

Chorioptic mange is caused by infestation with Chorioptes ____; where does the mite usually live?

Answer 43

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.

Question 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.

Answer 44

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.

Question 45

What is the most common cause of colic in a newborn foal?

Answer 45

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.

Question 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?

Answer 46

sacroiliac luxation/subluxation

Question 47

whats a good tx for a horse with sand enteropathies

Answer 47

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.

Question 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.

Answer 48

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.

Question 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.

Answer 49

Gonitis

Question 50

there are 3 PA toxicity hallmarks we see in liver biopsy

Answer 50

megalocytosis, periportal fibrosis, and biliary hyperplasia

Question 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.

Answer 51

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.

Question 52

What is the treatment of choice for a carpal hygroma in a horse?

Answer 52

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.

Question 53

Fistulous withers refers to inflammation of the

Answer 53

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.

Question 54

The most common congenital cardiac abnormality in the horse is ____

Answer 54

Ventricular septal defect

Question 55

Which antibiotic is contraindicated in foals?

Answer 55

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.

Question 56

About what percentage of a horse’s dry matter intake should be protein for an adult horse with maintenance requirements?

Answer 56

12%

Question 57

what is normal PaCO2?

Answer 57

40

Question 58

What is this ?

Answer 58

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.

Question 59

Calcium carbonate stones in horses have a higher likelihood of forming in _____ urine

Answer 59

Calcium carbonate stones in horses have a higher likelihood of forming in alkaline urine

Question 60

Answer 60

Strongylus vulgaris. A number of anthelmintics are effective including benzimidazoles, pyrantel and ivermectin.

Question 61

Strongylus edentatus and Strongylus equinus have one BIG things in common, what is it

Answer 61

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.

Question 62

where do Chorioptes equi mites like to hang out ?

Answer 62

around the foot and fetlock. It causes a pruritic dermatitis that can cause the formation of papules, crusts, thickened skin, as well as alopecia.

Question 63

what are the signs associated with these toxicities ?

• St. John’s wort
• Blue-green algae
• Slaframine
• cantharidin

Answer 63

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.

Question 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.

Answer 64

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.

Question 65

Centaurea solstitialis, aka yellow star thistle causes:

Answer 65

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.

Question 66

These are all flies that bug the horse, what does the horse show when they’re around?

• Culicoides
• Tabanus flies and Chrysops

Answer 66

• 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

Question 67

Which vx in the horse is associated with serum hepatitis

Answer 67

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.

Question 68

Oak poisoning in horses causes all the following except _____________.

Colic

Renal failure Correct Answer

Death

Hemorrhagic diarrhea

Tenesmus

Answer 68

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.

Question 69

when a farmer tells you his horse has “scratches” wtf does he mean ?

Answer 69

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.

Question 70

wtf is “sweet itch”

Answer 70

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.

Question 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

Answer 71

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.

Question 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

Answer 72

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.

Question 73

Oleander is a ______ toxic

Astragalus is a _____ toxic

Answer 73

cardio - racing heart followed by low HR, arrhythmias, hyperK

Neuro - LOCOWEED causes cracker heels

Question 75

Which of these drugs has the greatest potential for causing acute renal failure in the horse?

Doxycycline

Methoxyflurane

Phenylbutazone

Rifampin

Answer 75

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.

Question 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

Answer 76

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.

Question 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

Answer 77

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.

Question 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

Answer 78

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.

Question 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

Answer 79

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.

Question 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

Answer 80

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.

Question 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

Answer 81

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).

Question 82

Which of the following causes liver failure when ingested by horses?

Fiddleneck

Astragalus

Bracken fern

Oleander

Answer 82

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.

Question 83

What does intoxication with these things cause?

• castor bean
• sweet pea
• red maple
• senecio/ groundsel
• black walnut

Answer 83

• 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

Question 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

Answer 84

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.

Question 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

Answer 85

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.

Question 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%

Answer 86

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.

Question 87

A horse gets into cow feed that contains the ionophore, monensin. What is your biggest concern?

Answer 87

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.

Question 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

Answer 88

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.

Question 89

TERMANOLOGY

• Scratches
• Summer sores
• Sweet itch
• Sweeney
• Ringbone

Answer 89

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.

Question 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

Answer 90

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.

Question 91

Equine herpesvirus-3 (coital exanthema) is a cause of which of the following?

Infertility in mares

Balanoposthitis

Abortion

Infertility in stallions

Answer 91

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.

Question 92

Which of the following parameters is NOT associated with a diagnosis of DIC?

Prolongation of Prothrombin Time (PT)

Elevation in D-dimers

Abbreviated (shortened) activated partial thromboplastin time (aPTT)

Decreased antithrombin III activity

Thrombocytopenia

Answer 92

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.

Question 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)

Answer 93

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.

Question 94

Fescue ingestion leads to

Red maple causes

St John’s wort causes

Pyrrolizidine alkaloids

Cantharidin causes

Answer 94

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.

Question 95

What are the three diagnostic parameters that horses need to meet in order to go to isolation ?

Answer 95

Diarrhea, fever, and neutropenia. Any 2 of the 3 diagnostic parameters qualify for isolation.

Question 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?

Intermittent jejunal intussusception

Clostridium difficile enteritis

Salmonella infection

Lawsonia intracellularis infection

Answer 96

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.

Question 97

Claviceps purpura is the causative agent for which of the following?

Aflatoxicosis

Ergotism

Moldy sweet clover poisoning

Moldy corn poisoning

Answer 97

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.

Question 98

Which of these is least likely to cause oligozoospermatism in a stallion?

Acute orchitis

Testicular hypoplasia

Old age

Testicular degeneration

Answer 98

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.

Question 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

Answer 99

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.

Question 100

Which of the following is not a common clinical sign of urolithiasis in horses?

Polyuria

Dysuria

Hematuria

Pollakiuria

Answer 100

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.

Question 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

Answer 101

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.

Question 102

fiddleneck consumption causes …

Answer 102

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.

Question 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 _____, _____ ,______

Answer 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 carbohydrates, proteins, and fat are key components. (Dextrose, amino acids, and lipids)

Question 104

What are the two most common NSAID toxicoses seen in the horse?

Answer 104

Renal papillary necrosis and right dorsal colitis

Question 105

Equine viral arteritis can be transmitted by which of these routes?

Fecal-oral

Through open wounds

Venereally

Blood-sucking arthropods

Answer 105

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.

Question 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

Answer 106

The correct answer is bracken fern. Bracken fern will result in thiamine deficiency

Question 107

Which medication would be appropriate to administer to promote hemostasis?

Low-Molecular Weight Heparin (LMWH)

Aspirin

Aminocaproic Acid

Tissue Plasminogen Activator (tPA)

Answer 107

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).

Question 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?

Answer 108

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.

Question 109

A 23 year old horse is most likely to have what type of valvular regurgitation?

Aortic regurgitation

Tricuspid regurgitation

Pulmonic regurgitation

Mitral regurgitation

Answer 109

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.

Question 110

Which of these vaccines administered intramuscularly is most likely to cause a local reaction at the injection site of a horse?

Answer 110

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.

Question 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?

Answer 111

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.

Question 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.

Answer 112

Cerebellar abiotrophy

Question 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

Answer 113

Less than 2.5 mmol/L

Question 114

What is the most common cause of maxillary sinusitis in a horse

Answer 114

Tooth root abscess

Question 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

Answer 115

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.

Question 116

Approximately how long does it take for spermatogonia to mature to sperm in the stallion?

Answer 116

60days

Question 117

What is the most common cause of blindness in horses?

Equine recurrent uveitis

Cataract(s)

Trauma

Bacterial ulcerative keratitis

Fungal ulcerative keratitis

Answer 117

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.

Question 118

Approximately how long does it take for spermatogonia to mature to sperm in the stallion?

Answer 118

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.

Question 119

How is equine viral arteritis transmitted?

Venereally

Tick

Transplacentally

Mosquito

Answer 119

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.

Question 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

Answer 120

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.

Question 121

What breed of horse is predisposed to development of recurrent uveitis and equine night blindness?

Arabian

Quarterhorse

Thoroughbred

Appaloosa

Answer 121

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.

Question 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

Answer 122

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.

Question 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

Answer 123

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.

Question 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

Answer 124

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.