Dear Amy:
 
>Okay, I have a question in here somewhere- I was told that if he perked up
>on the pred, and then crashed a week or two later then he probably needs
>the Percorten too?  (it would have wore off by then) Should I have a test
>done to see where his hormones exactly are at, considering his continued
>pickyness?
 
The time table in which ferrets show signs of adrenal insufficiency
following bilateral adrenalectomy is not really established in black and
white; nor is a standard therapeutic protocol.  Ferrets that appear to
"crash" a week or so following surgery should first off receive a blood
test to look for evidence of electrolye imbalance (the cardinal sign of
hypoadrenocorticism in ferrets.) Mineralocorticoids such as Percorten and
Fluorinef are indicated if significant electrolye imbalances are seen at
this time which will likely include profound depression of sodium values,
or abnormalities in the ratio of sodium to potassium.  If electrolyte
values are within the normal range, then it is probably more appropriate
to start with prednisone alone (which should help in about half of these
cases).  Prednisone is easy for owners to administer orally and is quite
inexpensive.  In cases in which significant improvement in status is not
seen, or followup bloodwork shows a significant downward trend in sodium,
then Percorten or Fluorinef may be added.  About 25% of bilateral
adrenalectomies require both prednisone and some form of depot
mineralocorticoid.
 
Measurement of levels of estrogens in ferrets is of little benefit in the
diagnosis of hypoadrenocorticism.  In properly bilateral adrenalectomized
ferrets, estrogen levels should be zero.  It is not the lack of estrogen
that is making them crash at this point, but the level of the
mineralocorticoid aldosterone.  To my knowledge, aldosterone testing is not
available in ferrets, nor have normal ranges been established.  So we look
at the electrolytes, especially sodium as an indicator, and use clinical
responses to the injection of replacement hormones to make the diagnosis
of hypoadrenocorticism (Addison's Disease.)
 
With kindest regards,
Bruce Williams, dVM
[Posted in FML issue 3302]