Will Falconer, DVM Moderator
Hi Merrick,
First, I'd be quite concerned with Medrol for anything but emergency, very short term use. It's a corticosteroid, and they are supremely good at suppressing symptoms. The end result of suppression is often worse disease than what you suppressed.
And, I'm a broad brush stroke person, so poisons in general, but especially if you're warned about human exposure (Advantage) are never even on my short list for pets, Comfortis included.
Flea Busters guarantee no fleas for a year! Hard to beat that, and it's a borate compound, so quite safe, even if accidentally ingested.