Several years ago I was using Hartz Flea and Tick topical on my cats. They developed a fatal condition. It was not until a veterinarian that I used because our’s was out of town that we found out that it was the Hartz that was killing our cats. I contacted Hartz and, of course, they denied any ingredient that would harm an animal. Well…permethrin was the lethal ingredient that killed my cats, but like I said, Hartz wouldn’t admit to this. I even had the EPA investigate and of course no further course of action was indicated. Hartz is a big company and I am almost positive that the EPA didn’t want to ruffle their feathers. When I go into a store that sells pet products, I always look for Hartz topical for cats and don’t see it . . . that indicates to me that Hartz killed my cats because they don’t manufacture it any longer . . . at least in my area. Thanks for listening.