If I can't have my first guess (bear cub with 7 year old's nine iron up its butt) then I'm guessing fisher with tail damage. I've see one cat with mange/fleas/mites which lost all the hair on its tail except for a bit at the end and another with much the same due to dog attack. (Although it would take a hell of a dog to stri the fur from a fisher's tail.) I don't think pigs' tails are nearly that long. Also, it's fisher breeding season, and where they are scarce, they roam a long way to find a mate. (But then, don't we all.)