Veterinary Pharmacology Drugs Practice Test

The concept being tested is how boosting dopamine in the brain can help manage canine cognitive dysfunction. Selegiline is the drug that does this by selectively inhibiting MAO-B, the enzyme that breaks down dopamine. With MAO-B blocked, dopamine levels stay higher in brain circuits involved in learning, memory, and behavior, which can improve cognitive function and daily activities in older dogs. It’s a targeted approach that works well for CCD because it directly addresses the dopaminergic deficit seen with aging brains, and at therapeutic doses it has fewer dietary interaction risks than non-selective MAO inhibitors.

Other options don’t act on this dopaminergic mechanism. Fluoxetine is an antidepressant affecting serotonin, not an MAO-B inhibitor for CCD. Diazepam is a benzodiazepine that sedates and can worsen some CCD symptoms. Enalapril is an ACE inhibitor used for cardiovascular conditions and has no role in treating CCD.