The prescription stuff I had for Luna would kill a cat in a heartbeat, which is OK if you ask me.
You put drops onto the skin and rub it in from the back of their head to tail. Soaks in fairly quick and is waterproof after a short time.
I use to take her swimming in the Muskegon River. Boy, did she like that!
Much more expensive than OTC tho, but it worked well.
