Lin writes
 
>If I recall, it was said that it has been proven that adrenal disease
>is caused by too early neutering &/or improper lighting conditions.
 
Actually, the direct cause of adrenal disease has been shown to be LH
(luteinizing hormone).  (Note: I prefer the term "shown" rather than
"proven".)  Normally, LH produced in the pituatary gland stimulates the
gonads to product sex hormones, which lead to changes that shut off the
production of LH.
 
When there are no gonads, there is no feedback mechanism to shut off the
LH.  Now it turns out that in ferrets, the adrenal glands also have LH
receptors, and the constant stimulation can eventually cause hyperplasia
(which is an overgrowth of cells) which can lead to adrenal disease.
 
In ferrets, melatonin also is part of the mechanism that controls LH
production.  In short day/long night conditions, more melatonin is
produced, which reduces LH production and brings a whole ferret out of
heat.
 
Lin, I've had 6 ferrets that were not neutered until 5 1/2 to 8 months
old.  I've been covering my cages for several years now, and the ferrets'
favorite sleeping places are the dark drawers of my husband's old oak
desk.  Yet all 6 of these ferrets have had adrenal disease, as well as
the 2 early neuters.
 
One problem is that my ferret cage is in the living room.  The ferrets do
not go to bed until 9 or 10 pm, and they get up when I do at 6 or 7 am.
This is a long day/short night cycle, even though must of the rest of
the time is also spent in darkness.  Even brief exposures to light can
interrupt melatonin production.
 
To summarize: Neutering (at ANY age) and not enough long night cycles are
two conditions that can result in persistent overproduction of LH, which
can (and note the CAN) lead to adrenal disease.  This will not happen in
all ferrets.  We all know Smoking Causes Cancer, but there are always
examples of people who smoked 2 packs a day and lived to be 90 when they
were hit by a bus.  Other factors, such as genetics, are no doubt
involved.
 
The importance of this discovery is that it helps us understand what
conditions lead to adrenal disease, and how the current treatments work.
This can lead to better use of existing treatments, to new treatments,
and perhaps to ways to PREVENT the disease.
 
I really look forward to Dr. Murray's presentation in Toronto to learn
more details of this!
 
Please note, I am most certainly NOT a vet, but I have a Master's
degree in Chemistry from Princeton.  Some of the above may be
oversimplification, but I believe it provides the basic information
more or less accurately.  Those with details or corrections are welcome
to add them!
 
Linda Iroff
International Ferret Congress
http://www.ferretcongress.org
[Posted in FML issue 5216]