DVM Large Animal Medicine 2 — Questions and Answers
Question 1: A cow presents with right-sided ping on auscultation-percussion between ribs 9-12, decreased milk production, and anorexia. What is the most likely diagnosis?
- Left displacement of the abomasum
- Right displacement of the abomasum (Correct answer)
- Cecal dilation/volvulus
- Rumen tympany
Correct answer: Right displacement of the abomasum
Right displacement of the abomasum produces a characteristic 'ping' on auscultation-percussion over the right paralumbar fossa and is associated with decreased production and inappetence.
Question 2: Which of the following is the most common cause of shipping fever (bovine respiratory disease complex) in feedlot cattle?
- Pasteurella multocida alone
- Mannheimia haemolytica following viral stress (Correct answer)
- Histophilus somni as primary pathogen
- Mycoplasma bovis as sole etiology
Correct answer: Mannheimia haemolytica following viral stress
Bovine respiratory disease complex most commonly results from Mannheimia haemolytica opportunistically infecting cattle stressed by viral pathogens such as BRSV, BHV-1, or PI-3.
Question 3: A horse presents with acute onset of severe colic, complete absence of gut sounds, and gastric reflux of 8 liters. Rectal palpation reveals a tightly distended viscus in the right dorsal abdomen. What is the most likely diagnosis?
- Large colon impaction
- Right dorsal displacement of the large colon
- Small intestinal strangulating obstruction (Correct answer)
- Cecal impaction
Correct answer: Small intestinal strangulating obstruction
Severe colic with gastric reflux, absent gut sounds, and a distended viscus on rectal palpation is classic for small intestinal strangulating obstruction, which rapidly progresses and requires emergency surgery.
Question 4: In bovine ketosis, which metabolic parameter is MOST consistently elevated in blood?
- Glucose
- Insulin
- Beta-hydroxybutyrate (Correct answer)
- Bicarbonate
Correct answer: Beta-hydroxybutyrate
Beta-hydroxybutyrate (BHB) is the most reliable blood marker for ketosis, with levels >1.2 mmol/L indicating subclinical ketosis and >3.0 mmol/L indicating clinical ketosis.
Question 5: A ewe in late gestation is found recumbent, blind, and paddling. Blood glucose is 1.2 mmol/L. What is the most likely diagnosis?
- Hypocalcemia (milk fever)
- Pregnancy toxemia (Correct answer)
- Polioencephalomalacia
- Listeriosis
Correct answer: Pregnancy toxemia
Pregnancy toxemia in ewes occurs in late gestation due to negative energy balance, resulting in hypoglycemia, ketosis, and neurologic signs.
Question 6: Which nerve is most commonly damaged during dystocia in cattle, resulting in the cow being unable to extend the hind limb and knuckling at the fetlock?
- Femoral nerve
- Sciatic nerve
- Peroneal (fibular) nerve (Correct answer)
- Tibial nerve
Correct answer: Peroneal (fibular) nerve
The peroneal nerve is the most commonly damaged nerve during bovine dystocia, causing inability to extend the digit and knuckling at the fetlock while the cow can still bear weight.
Question 7: A horse develops purple-red discoloration of the muzzle and coronary bands along with vesicles and erosions in the mouth after being moved to a new pasture. Which condition should be ruled out first?
- Equine herpesvirus-1 infection
- Vesicular stomatitis (Correct answer)
- Purpura hemorrhagica
- Photosensitization
Correct answer: Vesicular stomatitis
Vesicular stomatitis is a reportable foreign animal disease that causes vesicles and erosions on the muzzle, coronary bands, and oral mucosa in horses, and must be ruled out before considering other differentials.
DVM Large Animal Medicine 2
A cow presents with right-sided ping on auscultation-percussion between ribs 9-12, decreased milk production, and anorexia.
What is the most likely diagnosis?