Frontline and Advantage are the best, but fleas are building up an immunity to them. I used both (separately) on my cats, and they killed ALMOST all the fleas... and then they just came back. The vet prescribed me Revolutions which still works really well (not as well as Frontline specifically...
My cat, Tickle Cricket, is about a year and a half old.
I feel I need to provide some background information, as this really is turning to be quite the mystery.
Tickle was bought from a Pets Plus (or some place like that) as a kitten. Tickle has chronic diarrhea, though is very smart and...
