I picked Hartz flea and tick back over the summer, to try over the winter when I didn’t think I really needed to use Advantage. I applied it to our 2 cats, SLY and TROUBLE yesturday. Within 4 hours SLY started having a seizure, we took her to the Emergence Hospital Vet and as we walked in the door the girl working their said ” Let me guess, you applied an over the counter flea medication!”, I just looked at her, because I couldn’t believe she new. 2 hours later we took TROUBLE. Both cats were keep over night for Trimmers and seizures. Trouble got to come home, but poor Sly is really sick, and had to go to our family Vet. She is shaking so hard, we are praying she will make it. So, by trying to cut corners, last night cost $577.00 for treatment, Sly is estimated to run around $300 today, and possibly go back to the Emergency Vet again tonight. I really wish I would have Known about this ahead of time. I will be telling everyone I know about this….