well i dont know about the Advantix being deadly to cats, seeing as i have a cat and i have used it since it first came out, with the recommendation of my vet, never once has bei-jing ever had any problems. I dont use it on her, i have only used it on the dogs, but she has never been sick or anything from it. I have tried frontline before and it just does not work as well as Advantix in my opinion. It keeps all of the fleas,ticks, and mosquitios away, Ginger when she was alive was extremely allergic to fleas and mosquitos and thankfully as long as she had it on her she never had any problems. I dont know what part of florida other people are in, but where I am, it works just fine.