DVM Large Animal Medicine 3 — Questions and Answers
Question 1: A Thoroughbred racehorse presents with exercise intolerance and dark red-brown urine after intense exercise. CK is markedly elevated. What is the most likely diagnosis?
- Equine infectious anemia
- Exertional rhabdomyolysis (tying-up) (Correct answer)
- Immune-mediated hemolytic anemia
- Pyelonephritis
Correct answer: Exertional rhabdomyolysis (tying-up)
Exertional rhabdomyolysis causes muscle breakdown leading to markedly elevated CK, myoglobinuria (dark urine), and exercise intolerance in horses.
Question 2: What is the recommended first-line treatment for hypocalcemia (milk fever) in a recumbent dairy cow?
- Oral calcium bolus alone
- IV calcium borogluconate infused slowly (Correct answer)
- IM calcium gluconate
- Calcium-phosphorus dietary supplementation only
Correct answer: IV calcium borogluconate infused slowly
IV calcium borogluconate infused slowly is the standard treatment for clinical hypocalcemia, restoring serum calcium rapidly; cardiac monitoring is essential during infusion.
Question 3: Which parasite is the primary cause of 'bottle jaw' (submandibular edema) in sheep and goats in the southeastern United States?
- Dictyocaulus filaria
- Haemonchus contortus (Correct answer)
- Ostertagia ostertagi
- Fasciola hepatica
Correct answer: Haemonchus contortus
Haemonchus contortus (barber pole worm) causes severe blood-sucking abomasitis leading to hypoproteinemia and submandibular edema (bottle jaw) in small ruminants.
Question 4: A beef cow is found with a protruding red mass from the vulva after calving. The mass is approximately 30 cm diameter, edematous, and has visible caruncles. What is the diagnosis?
- Vaginal prolapse
- Uterine prolapse (Correct answer)
- Rectovaginal fistula
- Vulvar hematoma
Correct answer: Uterine prolapse
Uterine prolapse is identified by the presence of caruncles (cotyledons) on the exposed tissue and occurs shortly after parturition, requiring immediate replacement or amputation.
Question 5: Which vaccine component is most important for preventing type C enterotoxemia (overeating disease) in sheep?
- Clostridium perfringens type D toxoid
- Clostridium perfringens type C toxoid
- Clostridium tetani toxoid
- Clostridium perfringens types C and D toxoid combined (Correct answer)
Correct answer: Clostridium perfringens types C and D toxoid combined
CDT vaccine (Clostridium perfringens types C and D plus tetanus toxoid) is the core small ruminant vaccine, providing protection against overeating disease and tetanus.
Question 6: A horse with Cushing's disease (PPID) is most likely to test positive on which diagnostic test?
- Low-dose dexamethasone suppression test (failure to suppress)
- High-dose dexamethasone suppression test (failure to suppress)
- Basal ACTH elevated, especially in fall (Correct answer)
- Urine cortisol:creatinine ratio
Correct answer: Basal ACTH elevated, especially in fall
Elevated basal ACTH, particularly during the fall seasonal rise (August-October), is the most practical and sensitive diagnostic test for equine PPID.
Question 7: A dairy herd has multiple cows with chronic weight loss, intermittent diarrhea, and hypoproteinemia. Fecal PCR is positive for Mycobacterium avium subsp. paratuberculosis. What is the condition?
- Bovine viral diarrhea (BVD)
- Johne's disease (paratuberculosis) (Correct answer)
- Salmonellosis
- Ostertagiasis type II
Correct answer: Johne's disease (paratuberculosis)
Johne's disease is caused by MAP and produces granulomatous enteritis leading to protein-losing enteropathy with chronic diarrhea and progressive weight loss in adult cattle.
DVM Large Animal Medicine 3
A Thoroughbred racehorse presents with exercise intolerance and dark red-brown urine after intense exercise.
CK is markedly elevated.
What is the most likely diagnosis?