Coming home this morning, petting my cat I saw there was a flea hanging out on his neck. What the heck, he’s an indoor cat. Never having a flea problem in his whole life I quick ran and got Hartz Ultraguard for cats. Following the age, weight guidelines, and proper directions for my cats not even 10 seconds later my one cat was starting to heavily drool from the mouth. I threw both my cats in the tub and immeditaley began to wash them with dish soap. Between getting the oncall number for the vet, my husband found a link to this page and what to look out for and confirm we did the right thing. I scrubbed them multiple times, and towel drying them not daring to let them lick themselves dry before their fur was completely dried out. As soon as I washed the product off, my cat stopped drooling. She was shaking for about 20 minutes after the ordeal, but is fine. I will never be using another Hartz product again.