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]