I used Hartz UltraGuard Pro Flea and Tick Drops as directed on my 2 1/2 year old cat on 5-9-11. She started scratching at her neck immediately and licking constantly. Her neck, her feet, her back everything. By morning she was wheezing and had respiratory symptoms. She also felt warm and was just NOT herself. The respiratory symptoms seemed to subside but the constant scratching continued. We have bathed her for the last 3 days and she continues to scratch and scratch. She is shedding so much hair from all over her body, more than she ever did before. I found this site on the 10th and I am so sad and mad at myself for doing this to her. The Vet has advised some prednisone for her discomfort. Of course, I bought this stuff and because it was cheaper. I have written the Attorney General of my state as well as Hartz. I will NEVER use a Hartz product again.