I would consider both that he was not neutered correctly, or that he is becoming adrenal. A vet can palpate the adrenals and tell if they are big, but after that, is the Tenessee Panel still being done to test adrenal ferrets? All of mine that have become adrenal showed signs of adrenal disease long before fur loss. They showed it through mating 'rituals'. Excessiving licking of a females' ears, then ear sucking/biting, and then biting the back of the females' necks and holding, attempting to 'you know what' :) Laryssa [Posted in FML 5875]