What medication is used to treat old-dog dementia?

The correct choice for treating old-dog dementia is Anipryl, which is the brand name for Selegiline. This medication is a selective monoamine oxidase inhibitor (MAOI) and is specifically indicated for the management of canine cognitive dysfunction syndrome (CDS), often referred to as old-dog dementia. Selegiline works by increasing the levels of certain neurotransmitters in the brain, such as dopamine, which may help improve cognitive function and behavior in aging dogs.

In the context of this question, while Selegiline and Anipryl refer to the same active ingredient, Anipryl is the more commonly recognized name for veterinary usage, making it the ideal selection here. Other medications like phenobarbital are primarily used as anticonvulsants and would not address the cognitive decline associated with dementia. Prozac, an antidepressant, is sometimes used for behavioral issues, but it does not directly target the specific neurological aspects of canine cognitive dysfunction. Therefore, Anipryl (Selegiline) stands out as the appropriate choice for this condition.