I used Hartz Ulter Guard Plus Spray. No reaction at first then with in about an hour she started to hide and foam at the mouth.Could not stop licking and drooling excessively from her mouth. She climbed behind the TV and began to shake.It was the middle of the night so no vet to go to. I washed her as well as I could. For the next 2 days she drooled and had all most no appetite. She was a strong 11 month old cat weighing 8 pounds. She is now 6 pounds and is still not the same over a week later.