BCSE Large Animal Internal Medicine 3

Question 1

A 3-week-old calf presents with profuse watery diarrhea, severe dehydration, and weak suckle reflex. Blood gas shows pH 7.08, bicarbonate 8 mEq/L, and strong ion gap elevation. Which pathogen is most consistent with this clinical picture in calves of this age?

Accepted Answer

Cryptosporidium parvum

Answer

Cryptosporidium parvum is the predominant cause of profuse, watery scours in calves aged 5–21 days with severe metabolic acidosis due to D-lactic acid production.

Question 2

Which clinical sign is pathognomonic for tetanus in horses?

Accepted Answer

Trismus (lockjaw) with erect ears and tail elevation

Answer

The combination of trismus, risus sardonicus (facial muscle contraction), erect ears, tail elevation, and generalized extensor rigidity triggered by stimuli is pathognomonic for tetanus.

Question 3

Left displacement of the abomasum (LDA) in dairy cows most commonly occurs in which time period relative to calving?

Accepted Answer

First 6 weeks postpartum

Answer

LDA occurs most commonly in the first 6 weeks after calving when the rumen contracts post-partum, leaving space for the gas-filled abomasum to displace leftward.

Question 4

A 10-year-old mare in the third trimester of pregnancy presents with sudden onset of severe weakness, recumbency, and muscle trembling. Serum chemistry shows calcium 5.8 mg/dL. Which treatment should be administered immediately?

Accepted Answer

Slow IV calcium borogluconate

Answer

Hypocalcemia in late-gestation mares is treated with slow IV administration of calcium borogluconate while monitoring heart rate to avoid cardiac arrhythmias.

Question 5

Equine recurrent uveitis (ERU) is most strongly associated with infection by which pathogen in endemic areas of the US?

Accepted Answer

Leptospira spp.

Answer

Leptospiral infection is the most common identifiable cause of ERU, with Leptospira antibodies and organisms frequently found in vitreous humor of affected horses.

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE Large Animal Internal Medicine 3