
Please note: I am not a ferret expert, and I did not write, nor did I
independently verify, all the information in this file.  I have done
my best to include only accurate and useful information, but I cannot
guarantee that what is contained in this file, whether written by me
or by one of the contributors, is correct, or even that following the
advice herein won't be harmful to you or your ferret in some way.  For
advice from an expert, you may wish to consult one of several books
available, or, especially in the case of a suspected medical problem,
a veterinarian who is familiar with the treatment of ferrets.

FERRET MEDICAL FAQ -- ADRENAL DISEASE

Last modified: 3 May 96
Version: 1.7.1


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Subject: CONTENTS

*** Adrenal disease ***

(1) Adrenal Disease in the Ferret (Dr. Williams)
(2) Adrenal Adenoma or Adenocarcinoma (Midwest Hospital)
(3) Diagnosing adrenal disease (Drs. Weiss and Williams)
(4) Blood tests for adrenal disease
(5) Statistics about adrenal tumors
(6) Options for ferrets with problems in both adrenals
(7) Hair growth after adrenal gland removal
(8) Ferret Medical FAQ copyright and redistribution information

------------------------------

Subject: (1) Adrenal Disease in the Ferret (Dr. Williams)

Written by Dr. Bruce Williams, DVM:

The following article may be reprinted by anyone desiring to
disseminate this information in a newsletter or non-commercial
publication.  This material may not be altered or changed in any way.
Under Title 17 of the U.S. Code, Section 105, copyright protection is
not available for any work of the United States Government.

     "My ferret is losing its hair."

     While hair loss in the ferret can occur from many causes, I would
like to concentrate on what is the most common and what is becoming
the most commonly talked about reason for serious hair loss --
proliferative lesions of the ferret adrenal gland.

     Ferrets with adrenal lesions - including areas of hyperplasia as
well as both benign and malignant neoplasms of the adrenal cortex -
typically all show the same clinical signs regardless of which type of
growth is present. These signs are fairly diagnostic, and in the
majority of cases, are so characteristic that no other diagnostic
tests are required before therapy is instituted.

     The signs of adrenal disease in the ferret are well documented
(Fox et al., 1987, Lawrence et al. 1993, Rosenthal et al., 1993,
Lipman et al, 1993) although the cause of these signs is still
somewhat unclear.  Adrenal lesions may be seen in animals ranging from
one to seven years of age, with the average being around 3.5 years. In
one study (Rosenthal, 1993), 70% of affected ferrets were female.
Hair loss, or alopecia, is by far the most common clinical sign in
affected ferrets.  Hair loss often begins at the tail, and progresses
forward over the trunk, flanks, and abdomen, until hair is only
present on the neck, head, and the extremities.  Additionally, in
spayed females, the vulva will often become swollen to the extent that
the owner may erroneously believe that the animal is in estrus.  A watery
mucus discharge from the vulva may also be seen in this animal.
(Vulvar swelling in a spayed female on its own is sufficient cause to
warrant abdominal exploratory surgery).  Other clinical signs that may
be seen in ferrets with adrenal lesions include increased scratching,
excessive drinking and urination, anemia, weight loss, and in
long-standing cases, difficulty in using the hind legs.

     The cause of the hair loss and vulvar swelling is not currently
known.  In other species with hyperadrenocorticism, high circulating
levels of adrenal corticosteroids cause the hair follicles to atrophy
and the skin itself to become thin, resulting in hair loss.  But since
we know that these ferrets do not have these high levels of cortisone,
this explanation does not suffice for what we see clinically.  A
plausible theory has been advanced by specialists at the Animal
Medical Center in New York City. (Rosenthal, 1993).  Citing the fact
that 36% of affected ferrets have high blood levels of estrogen, the
believe that early neutering (most ferrets in the U.S. are neutered
before six weeks of age) cause a population of cells in the adrenal
gland which have retained the ability to secrete gonadal hormones to
grow, in essence "filling the void".  High levels of estrogen are well
known to also cause hair follicle atrophy, and would also cause vulvar
swelling in females, as is seen in estrus.  In fact, Dr. Rosenthal has
demonstrated that serum estrogen levels are indeed higher in ferrets
with adrenal disease.

     The treatment for adrenal disease in ferrets primarily involves
removal of the affected adrenal gland.  [If money is an object,
Dr. Tom Kawasaki in Woodbridge VA, will probably do it for less than
$300 (and he has done many more than most vets).]  In most cases,
adrenalectomy is performed based solely on clinical signs.  Routine
pre-surgical blood work should be performed in all animals over 4
years of age, as would be done for any other type of surgical
procedure.  Special diagnostic tests which are used in other species
to diagnose adrenal disease are rarely of use in the ferret. Specific
testing for estrogen levels in the ferrets is not commonly available,
even at diagnostic labs, and in most cases is not necessary to confirm
the diagnosis.

      In most cases, one gland is noticeably larger than the other and
is removed.  For unknown reasons, the left adrenal gland accounts for
the majority of lesions (64%), with the right adrenal gland accounting
for 26%, and 8% of ferrets having disease in both adrenals.  Removal
of one adrenal gland is generally well tolerated in ferrets and in
most of these cases, if disease is confined to that gland, clinical
signs will cease (i.e., the hair will grow back and the swollen vulva
will diminish to its previous size). In animals with bilateral disease,
removal of one gland and part of another has been done, but carries a
more significant risk of post-operative complications.  (If a vet goes
in on an animal with classic signs of adrenal disease, he shouldn't
come out empty-handed.  If you can't tell, then take the left
one. [from another article by Dr. Williams]) Ferrets require at least
a portion of one adrenal gland to live.  (Just because both of the
adrenals are enlarged doesn't necessarily mean that both are involved.
I commonly see cysts in the right adrenal, which don't cause any
problem at all, but just make the adrenal larger.  ...  Just make sure
you get the adrenal looked at by a pathologist.
[from another article by Dr. Williams])

     The surgery itself is not excessively difficult.  Removal of the
left adrenal is fairly easy and has a low risk of complication.  Due
to the position of the right adrenal near several large blood vessels,
it is a more difficult surgery and requires considerably more
expertise on the part of the surgeon. As always, if your veterinarian
has little expertise in performing this surgery, it is wise to ask for
a referral to a more experienced surgeon. In cases in which surgical
excision of the offending adrenal gland is not an option, medical
treatment with certain drugs that kill off a large portion of the
cells of the adrenal cortex may be tried.  Unfortunately, this
medication is not specific for estrogen-secreting cells, and affect
all of the other cortical cells as well.  For this reason, this form
of treatment should be reserved only for those animals who are poor
surgical candidates.

     Unfortunately, not all adrenal surgeries end happily.
Postoperative mortality averages from 10% (Tom Kawasaki, personal
communication) to 12.5% (Rosenthal, 1993). The cause of the
post-surgical mortality is not known; most theories center on the
inability of the other, unaffected adrenal gland to produce enough
cortisol on short notice, i.e., the hyperfunctioning gland has caused
it to atrophy.

     On a personal note - while some owners believe that hair loss is
only cosmetic and would "rather not put their pet through the stress
of an operation", let me categorically state that the changes seen in
ferrets with adrenal disease are cumulative and progressive. Animals
with adrenal lesions do not just lose their hair - they also lose
muscle mass, and have little energy.  While the lesions themselves are
rarely life-threatening (in over one-hundred twenty cases, I have only
seen two cases of tumor metastasis), their clinical manifestations are
debilitating and greatly decrease the quality of a ferret's life.
(When I noticed the signs of adrenal disease in one of my ferrets who
was six at the time - I had the surgery done immediately.  The hair
has grown back, the vulva has reattained its normal size, and she is
more fit than ever.)

     Adrenal disease in the ferret is common, and if detected by a
watchful owner or a knowing practitioner, can be easily treated.

      Get those hairless ferrets checked, and have a festive
ferret-filled holiday season.

1.  Fox J.G, et. al.  Hyperadrenocorticism in a ferret.  JAVMA, 191:
343, 1987.

2.  Lawrence, H.J. et al.  Unilateral adrenalectomy as a treatment for
adrenocortical tumors in ferrets: Five cases (1990-1992).  JAVMA 203:
267-270, 1993.

3.  Lipman, N.S. et al.  Estradiol-17B-secreting adrenocortical tumor
in a ferret.  JAVMA 203(11): 1552-1554, 1 Dec 1993.

4.  Rosenthal, K.L. et al.  Hyperadrenocorticism associated with
adrenocortical tumor or nodular hyperplasia of the adrenal gland in
ferrets: 50 cases (1987-1991).  JAVMA 203: 271-275, 1993.

Bruce Williams, DVM
williamb@email.afip.osd.mil

------------------------------

Subject: (2) Adrenal Adenoma or Adenocarcinoma (Midwest Hospital)

from Ferret Senior Citizens and their Special Needs
Midwest Bird and Exotic Animal Hospital:

Adrenal Adenoma or Adenocarcinoma

     This cancer is almost as common as insulinoma and commonly occurs
along with it.  This is a cancer of the adrenal glands, which are very
tiny organs about the size of half a pea, located near the kidneys.
They produce very potent hormones that control a number of metabolic
functions in the body.  Most ferrets develop adenoma, which is the
benign form of the disease (which means that it does not spread to
other organs of the body). Adenocarcinoma is the malignant form that
we see less commonly.  Many ferrets develop the cancer in only one
gland.

     Signs are fairly specific and they are related to an
overproduction of corticosteroids and estrogen by the diseased
adrenal.  They include: hair loss over a portion or all of the body, a
decrease in coat quality (becomes dry and brittle), thinning of the
skin, thinning of the musculature of the body, lethargy, and
occasionally drinking more water and urinating more frequently.  The
hair loss may be intermittent, with periods of regrowth. The skin may
become intensely itchy and develop red patches, scaling and flaking.
Fat tends to accumulate in the abdomen and combined with the thinning
musculature and skin, gives a pot-bellied appearance to the animal.
Some spayed females may develop vulvar swelling as if they were in
heat again.

     Diagnosis is based primarily on the signs as described above.
Treatment of choice is the removal of the affected adrenal gland.
However, sometimes the disease is advanced, and both adrenals are
affected or other disease precludes the possibility of surgery.  In
these cases the use of a drug called Lysodren can be very effective.
It chemically destroys the adrenal tissue gradually until a more
normal hormone level is reached and the symptoms regress.  Even if no
treatment is elected for specific reasons, this tends to be a slowly
progressive disease, and many pets live 6 months to over 2 years,
bald, but happy.

------------------------------

Subject: (3) Diagnosing adrenal disease (Drs. Weiss and Williams)

According to Dr. Charles Weiss, DVM:

    There are many signs of adrenal tumors in ferrets.  The first sign
    is usually hair loss.  The loss of hair can involve only the tail
    or involve the whole body.  Other symptoms include pruritis (itchy
    skin), swollen vulva (females), return to sexual behavior in
    neutered males, skin that is thin and dry, and abdominal
    distention.  Unfortunately there is no reliable blood test.  It is
    important to note that the tests we use to diagnose adrenal gland
    problems in dogs and cats (called Cushings Disease -- a completely
    different disease) have been proven to be ineffective to diagnose
    adrenal tumors in ferrets.

    The bottom line is...  Yes, hair loss is usually the first symptom
    and the ferrets don't feel sick at this point.

And, from Dr. Williams:

    To start, the disease is not Cushings, because Cushing's disease
    is an oversecretion of cortisone, not estrogen from the adrenal.
    This is a common mistake that many vets have.  ACTH is not the
    hormone that is secreted, but estrogen, and ultrasound is not a
    very selective choice, becuase it has a high rate of false
    negatives.  [Thyroid and cortisol blood tests, including the ACTH
    stimulation test, won't tell you anything about adrenal-associated
    endocrinopathy -- adrenal disease -- in ferrets.] The best choice
    is the endocrine panel at Univ. of Tennessee in
    terms of catching silent or marginal cases.  Ultrasound may
    confirm a diagnosis, but contemplation of surgery should include
    more than an ultrasound exam, as so many adrenal lesions may be
    missed.

------------------------------

Subject: (4) Blood tests for adrenal disease

According to Dr. Bruce Williams, DVM, on 3 Feb 1995:

    The test is available to private practitioners from the
    Endocrinology lab at the University of Tennessee (615-974-5638.
    Ask for Betsy Bailey, and request the Ferret Adrenal Panel -
    she'll know what you are talking about).

    The ferret adrenal panel consists of assays for four hormones -
    dihydroepiandrosterone sulfate, estradiol, androstenadione, and
    17-OH-progesterone.  These are hormones and pre-hormones that are
    produced by the hyperfunctioning adrenals.  According to
    Dr. Rosenthal, in over 90% of cases - one or more of the hormones
    will be elevated.  In one case, when only the estradiol is up,
    however, you have to rule out an ovarian remnant (very rare), or
    the possibility of an intact ferret.  If more than one is up,
    though, it is very diagnostic of adrenal-associated
    endocrinopathy.

    Let me reiterate, however, that this test is mostly of use for
    ferrets in which the signs of adrenal disease are questionable.  I
    would still recommend surgery alone for cases of marked bilateral
    hair loss, or the presence of an enlarged vulva in spayed ferrets.
    I don' think the test adds any extra information to your diagnosis
    over these fairly obvious clinical signs.

    The cost to your vet for this test is $75.  0.5-1.0 cc of serum is
    required.  As a bonus, if the results are confusing to your vet,
    Dr. Rosenthal is available for consultation and interpretation at
    (212) 838-8100.



------------------------------

Subject: (5) Statistics about adrenal tumors

According to Dr. Bruce Williams, DVM:

    Recently, I completed a study of adrenal tumors in ferrets.  I
    studied all types and out of 86 tumors, 39 were malignant.  But of
    all 39 carcinomas, only 2 showed signs of metastasis.  The vast
    majority, even though they looked bad, were surgically removed and
    the animal went on to grow all its hair back and live for another
    several years.

    I recommend all adrenal tumors be removed, no matter how bad they
    look.  These tumors tend to look a lot worse than they are.

------------------------------

Subject: (6) Options for ferrets with problems in both adrenals

As Dr. Williams says above [1], ferrets need at least a portion of
one adrenal gland to live.  If your ferret has had one adrenal removed
and now has problems in the other one too, your best bet is probably a
partial adrenalectomy -- that is, have only part of the second gland
removed.

If that's not possible because too much of the second gland is
affected, a full bilateral adrenalectomy may be your only choice.  You
can contact Dave Ljung at <dxl@HPESDXL.FC.HP.COM> or Dr. Joseph Bock
of Golden, CO for more information on maintaining a ferret using
replacement hormones.

Lysodren, a medication commonly given to dogs and cats with adrenal
tumors, should be used only as a last resort.  Dr. Williams says,
"Most vets that are doing a lot of ferrets report poor response to
Lysodren, and in the cases that I have seen, the results are very
unpredictable."

------------------------------

Subject: (7) Hair growth after adrenal gland removal

Ferrets can take a long time to grow hair back, often not until their
next coat change.

According to Dr. Bruce Williams, DVM:

    There are several factors that may delay hair regrowth in ferrets
    following adrenalectomy.  One would be continued hyperactivity of
    the remaining adrenal.  A second reason may be the duration and
    severity of the presurgical hyperestrogenism.  As excessive
    estrogen causes atrophy of hair follicles, the hair follicles may
    take a long time to return to full (hair-producing) function.  It
    may also take the stimulus of a change in season which normally
    causes the shedding cycle to begin to bring her back into line.


------------------------------

Subject: Ferret Medical FAQ copyright and redistribution information

This compilation is copyright 1994-1996 by Pamela L. Greene.
It may be freely distributed by electronic, paper, or other means,
provided that it is distributed in its entirety, including this
notice, and that no fee is charged apart from the actual costs of
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Anyone who wishes to is encouraged to include a World Wide Web
hypertext link to the main Index page of this document set at
<URL:http://www.optics.rochester.edu:8080/users/pgreene/central.html>
wherever it might be appropriate.


