Which MAO-B inhibitor is used to treat canine cognitive dysfunction (Anipryl)?

• A. Amitriptyline
• B. Selegiline
• C. Tolcapone
• D. Rasagiline

Answer: (B)

Blocking MAO-B in the brain to preserve dopamine is the therapeutic idea for canine cognitive dysfunction. Selegiline is a selective MAO-B inhibitor approved for this condition (brand name Anipryl). By inhibiting MAO-B, it slows the breakdown of dopamine, helping maintain dopaminergic signaling that tends to decline with age, which can improve cognition and activity in affected dogs.

The other drugs don’t address this mechanism. Amitriptyline is a tricyclic antidepressant with broad effects that aren’t aimed at correcting dopaminergic loss in this context. Tolcapone inhibits COMT, not MAO-B, and isn’t the veterinary choice for canine cognitive dysfunction. Rasagiline is another MAO-B inhibitor but is not approved for this canine indication, so selegiline remains the recommended option.