NAVLE Feline Pharmacology and Toxicology 3 — Questions and Answers
Question 1: Acetaminophen (paracetamol) toxicity in cats primarily causes which two clinical findings?
- Acute renal failure and hypertension
- Methemoglobinemia and hepatic necrosis (Correct answer)
- Hypocalcemia and seizures
- Coagulopathy and thrombocytopenia
Correct answer: Methemoglobinemia and hepatic necrosis
Cats lack sufficient glucuronyl transferase to conjugate acetaminophen, leading to methemoglobinemia (muddy mucous membranes) and hepatic necrosis.
Question 2: A 4 kg cat requires ketamine for induction. Which statement about ketamine in cats is most accurate?
- It provides excellent visceral analgesia alone
- It must be combined with a benzodiazepine or alpha-2 agonist to prevent seizure-like muscle rigidity (Correct answer)
- It is hepatically metabolized to active metabolites that extend sedation
- It significantly depresses cardiovascular function
Correct answer: It must be combined with a benzodiazepine or alpha-2 agonist to prevent seizure-like muscle rigidity
Ketamine alone causes muscle hypertonicity and vocalization; co-administration of diazepam or medetomidine produces smooth induction.
Question 3: Which NSAID is FDA-approved for long-term pain management in cats in the United States?
- Meloxicam
- Ketoprofen
- Robenacoxib (Correct answer)
- Grapiprant
Correct answer: Robenacoxib
Robenacoxib (Onsior) is the only NSAID approved for longer-term use in cats in the US; meloxicam is approved for single-dose injection only.
Question 4: Xylitol ingestion in cats compared to dogs is best described as:
- Equally dangerous, causing hypoglycemia and hepatic failure
- More dangerous, causing acute renal failure in addition to hypoglycemia
- Less understood; cats appear more resistant to xylitol-induced hypoglycemia than dogs (Correct answer)
- Non-toxic; cats do not absorb xylitol from the GI tract
Correct answer: Less understood; cats appear more resistant to xylitol-induced hypoglycemia than dogs
Current evidence suggests cats are less susceptible to xylitol-induced hypoglycemia than dogs, though caution is still warranted and monitoring is recommended.
Question 5: A cat is receiving cyclosporine for feline atopic dermatitis. Which concurrent drug would most significantly increase cyclosporine blood levels?
- Phenobarbital
- Ketoconazole (Correct answer)
- Rifampin
- Dexamethasone
Correct answer: Ketoconazole
Ketoconazole inhibits CYP3A4 (the primary enzyme metabolizing cyclosporine), substantially increasing cyclosporine plasma concentrations.
Question 6: Which clinical sign most distinguishes feline metaldehyde (slug bait) toxicity from other tremorgenic toxicoses?
- Signs are worsened by sensory stimulation
- Hyperthermia is the predominant presenting sign
- Cats display continuous violent muscle tremors that are difficult to control (Correct answer)
- Mydriasis and tachycardia are the first signs
Correct answer: Cats display continuous violent muscle tremors that are difficult to control
Metaldehyde causes severe, relentless muscle tremors due to GABA inhibition; signs are often refractory to benzodiazepines alone.
Question 7: A cat with hypertrophic cardiomyopathy requires anesthesia. Which inhalant anesthetic is generally preferred for its cardiovascular stability in cats with cardiac disease?
- Halothane
- Isoflurane
- Sevoflurane (Correct answer)
- Desflurane
Correct answer: Sevoflurane
Sevoflurane has the least negative cardiovascular effects and most rapid induction/recovery among currently available inhalants, making it preferred in feline cardiac patients.
NAVLE Feline Pharmacology and Toxicology 3
Acetaminophen (paracetamol) toxicity in cats primarily causes which two clinical findings?