>I've had three bilateral adrenal surgeries, all three had cryosurgery.
>None needed hormone replacement
 
The adrenals make some products which are essential for survival.
Without them the individual dies.
 
No matter what the type of surgery done is, if enough living adrenal
tissue is left behind then hormonal replacement isn't needed.  Sometimes
that is unavoidable -- in fact, when it happens it is usually
unavoidable, and as you found often works out well.
 
It is alternatively possible to leave an adrenal behind which has
atrophied (as we had happen with one who had a diseased right one but the
left was atrophied).  This is rare and is more common when Lysodren has
been used long term (That is a med which almost no vets any longer use
for ferret adrenal growths because it tends to either not work at all or
too work too extremely and its primary focus is on the wrong part of the
adrenals for the types of adrenal disease ferrets get.) In this case an
Addison's Crisis can occur and hormonal replacement is essential to avoid
death.  In a crisis the vet may at first also give fluids and salts.
 
Hormonal replacement usually consists of a med to fix bad ratios of
electrolytes such as Florinef or Percorten, and a tiny bit of steroid
to help with fluid management.  The amounts often need adjusting till a
good level is found, then may need readjusting over time with changes
in activity levels, weight, or other physical stresses such as having a
severe illness.  Ashling's levels went down with decreased activity with
age then went up a bit when she had carcinoma.  A weight gain can also
require an increase.
 
If the adrenals come out cleanly then hormonal replacement is needed.
The reason that removing cleanly when possible is done is because even
though meds will then always be needed it is safer to remove all that
can be removed in case any of the tissue is malignant and there is no
way to know for sure if it is malignant till after the biopsy results
come back unless it is really extreme and then malignancy can be a better
guess though the type is still unknown without biopsy.
 
It always pays to biopsy.  If you don't know what is there you don't know
how to most effectively respond to it.
 
At times even when tissue is left behind there is a need for temporary
hormonal replacement so when in doubt some vets will give the meds
temporarily then retest electrolyte proportions later.  Apparently,
doing so doesn't hurt anything and it can stave off a potentially fatal
Addison's crisis.
 
Sometimes when tissue has to be left behind it may over-grow again and
then the choice is whether to debulk (remove the bulk of it) what is left
behind or start Lupron, at times in conjunction with other meds,
depending on the ferrets and any complications.  There are WONDERFUL
posts by Dr. Jerry Murray on such medications in both the FHL Archives
(See posts from AFERRETVET at http://fhl.sonic-weasel.org )
and FML Archives (see topic: JM FROM FHL in
http://listserv.cuny.edu/archives/ferret-search.html ).  I do not get to
carry over all vet posts sometimes because they say what has been said
before, or sometimes because other needs in life just make it impossible
to schedule in that time, but you will find most of these adrenal posts
in the FML Archives.
 
We ALWAYS make sure to have Florinef and Prednisolone handy when an
adrenal surgery has taken place.  It is an easy and cheap precaution.
 
Hope this helps clarify what it going on and why and when certain
measures are needed.
[Posted in FML issue 4393]