Just found this website. I had twice bathed my cat with hartz ultraguard foaming flea and tick shampoo. I also used an ultraguard one spot flea treatment on her. From time to time, she had had seizures and convulsions that would last a few minutes and then go away. Two weeks ago, she went into such a terrible seizure that she could not move for over an hour…she just dragged herself along the floor, trying to hide. I had to take her to the humane society to have her put to sleep. The vet I took her to after the first episode diagnosed her problem as thyroid related and tried to sell me a plan to treat it for a discounted price of $500. I am a poor man and could not ever hope to pay that. They charged me 90 bucks. I asked if it could be related to flea medicine and they said nah. Then today, two weeks after I lost my best friend of ten years, I find this site. I feel like I just got punched in the gut. I am angry at the vet, at hartz and at myself. What a heartbreaker.