My cat had fleas so I went to Walmart to get some flea products. It was a choice between two products and I chose Hartz. I put it on Tobey on a Monday night and by the next day she seemed drowsy. She was like that for a few days and then she got better. Then one day I found her under the bed, one week after I had put the flea treatment on her. I never knew about the dangers and now my cat is dead. Hartz is responsible without a doubt.