My husband and I thought our cat Zeek had fleas, We just wanted to try a cheap flea drop to take care of an fleas or eggs he might have. I purchased Hartz Ultra Guard Plus. Almost immediatly Zeek started acting strange. He wouldnt sit still and kept rolling around on the floor. I thought maybe he didnt like the feel of the drops. After awhile he was still acting strange. I am feel cautious with him as if he was my child. I knew something wasnt right. I looked up allergic reactions to flea drops and I found this web site. I immediatly wash his back. I kept a close eye on him all night and as of now he is acting like himself. I just want to thank everyone for writing their stories. I dont know what I would have done if anything more would have happened to him. Thank you again to everyone.