Neutering is a factor in the development of most cases of adrenal
disease (but not all since there have been whole ferrets, even young
whole ferrets with adrenal disease).

The paper by Dr. Nico Schoemaker which has been mentioned came out
years ago, as have two (hmmm, I think 3 now but I would have to
check...) others on the topic of adrenal disease in ferrets. You can
find the abstracts to help you tract them down by using PubMed, and
his dissertation is at the university's page that makes dissertations
public. Links can be found in past FML and FHL posts.

Neutering did NOT make adrenal disease inevitable. There appear to be
other factors affecting onset (and exposure to too little complete
darkness is discussed as a factor by other vets in the FML archives),
plus the rates of adrenal disease seen in ferrets seems to vary among
vets. We personally see about 1/3 of them in our family developing
adrenal disease, most of those of only one gland. That is over a 27
year timeframe of having ferrets in our family. I have heard similar
numbers from some vets, higher from others, and the rates reported by
people for their own ferrets vary widely. So, husbandry can play a role
WHEN THERE ARE FACTORS THAT INCREASE LH (Luteinizing Hormone) OUTPUT.

The three year aspect was the mean -- the average -- and the actual
ages of onset in Dr. Schoemaker's graph vary hugely -- enormous
standard of deviation involved, so don't take it as an absolute because
it could instead be 5 or more years after sterilization or even happen
the first year. (Early ones are more rare but in the U.S. increased
after fancies became so popular.) Two research mathematicians I ran it
by considered the deviation to be large enough for the graph to be of
low value. So, just take it as an average for the subset of neutered
ferrets who actually do develop adrenal disease, rather than treating
it as an absolute.

His current research is a life time study of a number of ferrets using
deslorelin implants to see several things including:
1. Does it become less effective over time in ferrets as it can in
humans or not?
2. Does it work as a way to temporarily chemically neuter a ferret
without having the adrenal disease (and one other research vet thinks
possibly insulinoma disease) increase in rate that accompanies
neutering by surgery?
3. Does it decrease the rates of adrenal disease (preventative) over
the population of animals studied or delay the age of onset, or both?

Deslorelin is a relative of Lupron but appears to be much better. It
is done as an implant and lasts far longer in the animal plus it is
cheaper. Currently, the U.S. has not approved Deslorelin in that
specific form for use in this country but the application to sell it
here was made about 3 years ago. Hopefully, that will happen before too
long. Such applications are like rule changes you wait, and you wait
and you wait and zzzzzzzzzzzzzzzzzzzzzzzzzz, and you wait, and then
suddenly you have to hurry up and rush about some other thing the
governmental agencies want almost immediately. Each time enough people
must jump and must provide the right needed info or all the earlier
work, even years of it, can go down the drain.

BTW, from what I have been told deslorelin implants, like Lupron Depot,
can be used WITH melatonin implants to more effectively tackle the
factors in more than one way.

Besides the neutering -- at ANY age though there *might* be some
changes that happen in females who stay whole past the one year mark
or past their first heat (hypotheses that have not been investigated
and are based upon some vets' observations), and besides several
medications such as the useful Lupron Depot, and Melatonin Implants.

One of the things under study is genetic differences. Dr. Bob Wagner
has found p53 variations that make tumor fighting difficult to
impossible in other species to be present in some U.S. ferret lines.
Dr. Michelle Hawkins (for whose team Bob Church collected an enormous
collection of ferret genetic specimens in his travels) has mostly been
studying MEN (multiple Endocrinological Neoplasia) genetics this far
but wants to expand into looking at other possible contributors.

Speaking of contributors I suspect that with the current economic
situation this, like so many other veterinary research projects, may
need more donations. I don't know for sure but she is based at U.C.
Davis. Since Bob has helped her and since I have known her for a great
many years (ever since she was one of the people to help us when
Hilbert developed his cystine uroliths) either of us could ask if
potential donors want to contact us, or you can look her up or use past
posts in the FML Archives in which she had me include her contact info
if you can contribute some funding. Ferret health research almost
always needs funding sources, not always, but so commonly that it is
not funny.

Sukie (not a vet)

Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html

[Posted in FML 6163]