So, I always use Advantage 2 on my cats and have never had a problem. I have a new rescue kitty who is about 9 or 10 months old and I put the advantage on him and he had a really bad reaction. He was laying on the couch in a puddle of his own drool, tongue out and eyes crossed. I thought he was dying. Vet said to bathe him in dawn so I did and he was much better within a few hours. Question is, would frontline be any different? I'm scared to try something else. I'm also looking into some alternatives to chemical flea treatments. I just didn't know if the frontline would cause the same reaction or not.