We could not figure out what was wrong with our cat after we gave her UltraGuard plus. She licked herself non stop for about 2 months afterwords starting the night we gave her the flea medication. She had licked most of her hair off and couldn’t even use her litterbox anymore. She was going to bathroom everywhere. We spent over $400 on vet bills including putting her to sleep. I was telling someone about our story and they asked if we used Hartz, because they had similar problems with their dogs. The one dog even developed epilepsy after flea medication. I asked my vet if the flea medication could have caused it before we put her to sleep, and I was told that was unlikely. Obviously, it appears my suspicions were correct.