The signs (tail hair loss and comedones) are common in ferrets with either
benign seasonal alopecia (which is adrenal-controlled) or with true adrenal
disease.  If he has suddenly become more aggressive or has more odor, these
signs argue in favor of true adrenal disease, maybe with testosterone
increase.  As far as tests go, both ultrasound and hormone assays have
merit.  In practicality the more experienced I've become the less I have
needed to rely on these tests.  I can palpate most enlarged adrenal.
If one is enlarged, I don't really care what the hormone assays say, as
some adrenal tumors are non-productive (no hormone output).  I always
remove a big adrenal.  Another simple test that's usually overlooked is
urinalysis-if he has a lot of squamous cells in the urine (via expressed
sample) then suspect estrogen elevation, (adrenal disease).  Estrogens
cause changes in the prostate which can be seen in the urine.  A good
history palpation and urinalysis allow me to confirm about 90% of adrenal
cases without expensive diagnostics.  Really good palpation skills are
difficult to acquire, however.
 
Also realize that a general blood profile should be run prior to any
adrenal surgery, both to determine anesthetic safety and also because over
half of my adrenal cases have other significant disease such as insulinomas
or inflammatory bowl disease.  Key tests to run include glucose (fasting
for 4 hours prior), ALT, GGT, Lipase, Globulin, BUN, Albumin and CBC.
These can detect a lot of previously unsuspected disease if one knows how
to interpret them.
 
Good Luck,
Mark Burgess DVM
[Posted in FML issue 3408]