Carolina, is his fur loss only on the tail?  Fur loss only on the
tail can be adrenal but more often is dermal: acne, dry skin, damaged
follicles form previous fur loss, etc.
 
Pet insurance: remember that as of this year they no longer cover
endocrinological problems in ferrets (adrenal, insulinoma, etc.).
 
Lighting: what is more important is 14+ hours of true darkness per 24
hours.  (No night lights, none of those green equipment lights, no power
strip lights, no lit-up clocks, etc.)  IT IS ONLY IN DARKNESS THAT THE
BODY MAKES MELATONIN and disrupting that darkness too often or having it
lessened reduces the amount of melatonin the body produces.  The body's
own melatonin levels affect numbers of hormonally related malignancies
with better levels reducing them, sometimes markedly, AND it seems to
prevent early on-set of some non-malignant endocrine disorders.  Ingested
melatonin looks to also be useful but it may not be as good as the body's
own produced in true darkness -- that is still not known.  You can read
some interesting posts about this if you search under words like darkness
or melatonin, esp. if you also use the "from" search as AFERRETVET
written just like that.  Just go to http://fhl.sonic-weasel.org/
which is the FHL Complete Archives and is not on the same server as the
FHL so it will NOT be down for about 6 days in the upcoming Smartgroups
serious maintenance which will take down the Ferret Health List starting
just about now...
[Posted in FML issue 4182]