BCSE Large Animal Internal Medicine 4

Question 1

A feedlot steer develops sudden onset neurologic signs including head pressing, aimless wandering, and blindness. Post-mortem reveals yellow-orange discoloration of the liver and brain. Which toxicosis is most likely?

Accepted Answer

Pyrrolizidine alkaloid toxicosis

Answer

Pyrrolizidine alkaloid toxicosis causes hepatic megalocytosis and progressive liver failure with secondary hepatic encephalopathy and characteristic yellowish liver discoloration.

Question 2

A 7-year-old warmblood gelding has a 2-month history of exercise intolerance, occasional muscle stiffness, and dark urine after light exercise. CK and AST are markedly elevated after exercise. A muscle biopsy shows abnormal polysaccharide accumulation. What is the diagnosis?

Accepted Answer

Type 1 polysaccharide storage myopathy (PSSM1)

Answer

PSSM1 is caused by a GYS1 mutation causing excess glycogen and abnormal polysaccharide accumulation in muscle, confirmed by muscle biopsy with periodic acid-Schiff staining.

Question 3

In the diagnosis of Johne's disease (paratuberculosis) in cattle, which test has the highest sensitivity for detecting shedding animals in the subclinical phase?

Accepted Answer

Fecal PCR

Answer

Fecal PCR has higher sensitivity than fecal culture for detecting subclinical shedders, with results available in days rather than the weeks required for culture.

Question 4

Which of the following is the most common cause of esophageal obstruction (choke) in horses?

Accepted Answer

Poorly soaked sugar beet pulp or hay cubes

Answer

Improperly soaked beet pulp or hay cubes that expand with saliva and water in the esophagus are the most common cause of choke in horses.

Question 5

Bovine leukemia virus (BLV) causes lymphoma that most commonly affects which organ system in adult cattle?

Accepted Answer

Abomasum and lymph nodes (adult form)

Answer

The adult (enzootic) form of BLV-associated lymphoma most commonly involves the abomasum, heart, uterus, and lymph nodes in cattle over 2 years of age.

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE Large Animal Internal Medicine 4