It may be the insulinoma that is causing the hair loss. Endocrine diseases can cause hair loss - with ferrets it is usually adrenals but i have seen uncomplicated insulinomas cause hair loss - is the ferret bald? it may be the heat or it may be seasonally. Dr T. Lightfoot mentioned in a lecture this year that part of the adrenal syndrome can begin with a season hair loss that progresses to hair loss with out regrowth. The adrenals may be big - but they may not be producing abnormal amounts yet - I would follow along and see what the levels are in 3 months. if increasing might need sx. I have seen some adrenal tumors that do not produce elevated hormones. good luck. Ben A. Otten, DVM 651 North Terrace Ave 3J Mount Vernon, NY 10552 (914) 664-3149 "let there be songs to fill the air" [Posted in FML issue 3507]