We been there. PYOBEN medicated shampoo, antimicrobial for dogs and cats did the trick. It contains BENZOYL PEROXIDE. Mousse approves of his new shiny tail. Squirrel approves too, now he can see his reflection. Squirrel needs counselling. We read about this in a ferret mag (forget which one) and our vet ordered it for us. We could not find any shampoo containing that stuff in any local stores. Pharmacists just scratched their heads (maybe they should try it). TJ & Caroline & ratniki. PS We use it only on the tail with a dunk and rub technique. Have NOT tried this on the whole critter. It may be too strong for use on the whole body. We use it as needed: twice in almost 6 months. [Posted in FML issue 2997]