From:
Sukie Crandall
Date: 2008-07-04 16:48:20 UTC
Subject: [ferrethealth] a primer on some aspects of insulinoma and of adrenal disease
To: fhl <ferrethealth@yahoogroups.com>
There still seems to be a LOT of confusion out there despite loads of
info available.
Here is an overview of careful research by endocrinologists and
veterinary endocrinological researchers has uncovered.
Insulinoma:
Rates not known
Cause not known
Hypotheses advanced by experts:
1. Prevention: Carbohydrates as a cause. Originated by Dr. Mark
Finkler who is a very careful and highly reputable researcher so he
very carefully notes in his paper that this is a hypothesis built from
other hypotheses. (He knows that I admire this frankness of his, BTW,
because I have told him.) Other hypotheses include one that
carbohydrates can cause diabetes in humans. The results on actual
studies for human health are actually all over the board. Some seem
to agree with the hypothesis, some seem to disagree, some seem to show
no effect. Except for ferrets who have certain medical problems, such
as a tendency to form cystine uroliths it doesn't appear to hurt
ferrets to follow the guidelines of that hypothesis, though, so a
dietary approach as a possible preventative is certainly reasonable to
try.
2. Melatonin and whether it may help or worsen things for ferrets with
insulinoma. This is also something where the results (in this case
faces by clinicians) vary a lot, so what can be done is to try the
oral forms to see what happens instead of immediately trying an implant.
3. Relationship to a form of adrenal disease. Pancreatic diseases
like insulinoma and diabetes are endocrinological diseases like
adrenal disease is and tend to occur around the same age. This could
be partly due to genetic vulnerabilities and partly due to that age
bracket. There may be other so far undiscovered shared factors. What
do appear to on rare occasions be more closely related are adrenal
disease and diabetes. As with the other things in this set of notes
there is loads more on this in the archives:
http://ferrethealth.org/archive/
4. Genetic vulnerabilities: Two possible genetic contributors to the
development of endocrinological diseases HAVE been found in U.S.
ferrets, and other possible genetic factors are hoped to be looked at
in the future. The ones found are MEN which stands for Multiple
Endocrinological Neoplasia which appears to significantly increase the
tendency to have endocrinological tumors in other species, and p54 (if
I recall the designation properly) which reduces the bodies ability to
stop endrocrinological tumors, including when most such cells as
killed -- in the very early stages before there are many of them. The
work on the first is by a team headed by Dr. Michelle Hawkins, and the
work on the second is by a team headed by Dr. Bob Wagner. Dr. Hawkins
is also heading a much larger study for which Mr. Bob Church has
recently been collecting genetic specimens in other parts of the
world, then the veterinary and genetic researchers at UC Davis will
work from those.
Reasonably well established: why some get diabetes after a while.
See archives.
Adrenal Disease:
Rate: unknown (Reports of there being studies showing rates were due
to a miscommunication and/or a note taking error. I have spoken
directly with the person, Dr. Mark Finkler, from whom that information
was said to come and he says there are no such studies, and that the
rates given aren't even anything like what he personally encounters.)
Cause: well established as being due to too much Luteinizing Hormone
(LH) being released for too long. Follicle Stimulating Hormone (FSH)
(which increases from the same causes and can't be slowed for the same
reasons) may also play a part. In research for both veterinary and
human health there are a large number of studies and each step is not
only demonstrated but independently confirmed. The reason it appears
so very much more often in neutered ferrets compared to whole ferrets
is simple. When the ferret begins to be exposed to more light (as in
Spring) the body's own production of melatonin in the pineal gland
decreases. The lowered levels of circulating melatonin signal the
pituitary to begin turning out more LH and FSH. Now, normally the
upshot would be mating and the result would be that the reproductive
organs would signal the pituitary to "shut up already" with the LH and
FSH and the levels of LH and FSH would decrease. Without those
reproductive tissues the neutered ferrets (who would face increased
rates of other health problems if they were not neutered) can't stop
the high levels of LH and FSH from causing harm. (Too high levels of
FSH have been associated with bone loss including in women who are
through menopause but I don't know if that is confirmed yet.) And
THAT is how adrenal tumors begin.
Prevention: Not all melatonin is equal and even the natural ones fail
to be effective after a while in some studies. The melatonin the body
produces itself in response to darkness seems to be best, implant
seems to be second best and oral least effective but better than
nothing. Melatonin can be used in conjunction with some stronger
treatments that are also under study for prevention: Lupron (Dr.
Cathy Johnson-Delaney and I think maybe Dr. Bob Wagner) and deslorelin
(Dr. Nico Shoemaker, and Dr. Bob Wagner, maybe others). There is also
a study currently underway to short circuit the hormonal
overproduction really, really early on. A new study has been begun
which -- if it meets hopes -- could be
wonderful, and that is to develop a vaccine that would hopefully
prevent the cycle that leads to adrenal tumors right at the
gonadotropin-releasing hormone (GnRH) level. Doctors Bob Wagner and
Mark Finkler are involved in that work and I think there are others
but do not know who.
Genetic vulnerabilities: see the section above in the insulinoma note.
Connection with pancreatic diseases: See the section above in the
insulinoma note.
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
[Non-text portions of this message have been removed]
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