I used to put Advantage on my furry kids including cats and dogs. I used it on my daughter's very first pet, a Siamese mix kitten dumped at a feedstore. I had never had any problems with Advantage but the first time I used in on the half grown kitten she got sick. I took her to the vets but he said it wasn't a reaction, she was sick from something else. The little kitty LOVED ferrets and slept with them. The next month when I put Advantage on her she was sick again and I rushed her to the vet. She died. The vet contacted the Advantage company. They said it wasn't the med. Necropsy showed nothing. Research on the internet showed that LOTS of cats had died from Advantage. The guilt I felt was overwhelming. I felt that I had killed her. My newly adopted daughter was desvastated......try to explain to a 9 year old that doesn't speak English why her kitten died....impossible. I never used Advantage again. I now use Revolution and have no problems. I have 15 ferrets and one tube does them all. I shake it real good and just put a drop on each....not the recommended dosage but it works. It kills everything (except the pet) including heartworm. I know that everyone has their own preference for flea meds so this is not to offend anyone. Just saying what works for me. Nancy and her 15 ferrets, 14 cats, 3 dogs, 6 rats, 6 hamsters, goldfish and a pre-killed mouse eating ball python.........oh ya......9 human children, 2 bio, 2 step, all grown and on their own and 5 adopted daughters, 4 of whom are TEENAGERS and it's school vacation....AWWWKK. I need a T-shirt that says "ferrets keep me from going insane".... [Posted in FML 6283]