I found a lost and lonely kitten out in the middle of the woods in the rain. Lost, soaked, and shivering she followed me to the car and jumped in. Took her home, gave a bath, and some food. combed her with flea comb, no fleas or ticks. went to store, bought food, litter and box, and a Hartz collar to keep fleas away. Less than two days later, she started to walk like she was drunk. i had noticed her cleaning herself and licking her chest just under the collar the night before. Researched online, found this site and other info, Removed the collar, gave her bath with mild dish soap. Within an hour she was doing better. Been two hours now and tomorrow morn will see how she is. Hate to think i caused her this problem, had i only known about these collars being bad for some cats…….. i never would have used it. Thank you for this site.