NAVLE Feline Pharmacology and Toxicology 5

Question 1

A cat receiving phenobarbital for seizure management develops a sudden increase in seizure frequency despite adequate serum levels. Which mechanism best explains this phenomenon?

Accepted Answer

GABA receptor downregulation develops with chronic phenobarbital use, reducing drug efficacy

Answer

Chronic barbiturate use can cause GABA-A receptor downregulation and tolerance, reducing seizure threshold despite unchanged serum drug concentrations.

Question 2

Which drug is the first-line treatment for feline arterial thromboembolism (ATE) prevention?

Accepted Answer

Clopidogrel

Answer

Clopidogrel (Plavix) is superior to aspirin for secondary prevention of ATE in cats with cardiomyopathy, as demonstrated in the FAT CAT study.

Question 3

Propylene glycol is present in some semi-moist cat foods and medications. Why is it contraindicated in cats?

Accepted Answer

It causes Heinz body formation and hemolytic anemia in cats

Answer

Cats are uniquely susceptible to propylene glycol-induced Heinz body hemolytic anemia because their hemoglobin contains eight SH groups versus four in dogs.

Question 4

A cat is presented for suspected oleander (Nerium oleander) ingestion. What is the primary mechanism of toxicity?

Accepted Answer

Inhibition of Na+/K+-ATPase causing cardiac glycoside toxidrome

Answer

Oleandrin and neriine in oleander inhibit Na+/K+-ATPase, causing hyperkalemia, bradyarrhythmias, and AV block similar to digoxin toxicity.

Question 5

Which statement about maropitant (Cerenia) use in cats is correct?

Accepted Answer

It is approved at 1 mg/kg SC once daily for nausea prevention

Answer

Maropitant is approved at 1 mg/kg SC in cats for nausea and vomiting; it blocks NK1 receptors and also provides visceral analgesia.

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE Feline Pharmacology and Toxicology 5