I recently used Ultraguard Onespot Flea & Egg Treatment by HARTZ. It says it’s for cats and kittens.My kitten immediately swung her head around and began licking at it incessantly. Kittens can reach around and lick between their shoulder blades. Within 2 hours of applying it my 12 week kitten began to curl up and roll all over, lost complete muscle control, she couldn’t stand, she’d scramble backwards then roll around repeatedly. She fell if she tried to get on her feet. This went on for 20 minutes then she looked horrible and was very weak. It happened a little more that evening and then I believe that was it. She was just such a mess afterward and so lethargic. It took a few days before she was almost back to her old self. I can only describe what she was doing as a seizure or many seizures. It was incredibly scary, I thought she was dying in front of me. I called Hartz and they advised that methoprene would not produce this reaction, my stupid vet said the same thing, he’s an idiot though. I’m extremely angry and I feel that there are enough complaints of reactions like this that Hartz needs to be called out in court. I’d like to know if anyone else has used this particular product with similar reactions in their pet.