In Digest 37 Bob Church raises some interesting questions about adrenal
disease in relation to furballs and to bone loss, followed by replies
from two vets, Karen Purcell and Bruce Williams:
 
 Subject: Bob C: Question for *ALL* the Vets regarding Adrenal Disease
          (And anyone else with the knowledge)
 
As some of you know, I a working on a morphometrics 'test' which will
separate populations of polecats from feral ferrets and pet ferrets.  As
a result, I have taking hundreds of measurements from ferret skeletons,
which are duly donated for that purpose (they will be donated to the
Smithsonian when the research is finished).  I am also creating a "photo
catalog" of various bone pathologies.  One shelter (which I leave unnamed
to prevent the type of animal activist letters I get on occasion) regularly
donates between 20 and 40 ferrets a quarter, along with notes to cause of
death (when known).
 
The first thing I do is a quick gross necropsy (they have all been frozen,
so I am rather limited in what I can do), and measure things like body
fat percentage, presence of lesions or lumps, skeletal or anatomic
malformations, etc.  The skeletal processing is as benign as possible, but
I won't detail it here for obvious reasons of taste.  One of the things I
do is open the gastrointestinal tract to look for hairballs or foreign
objects, as well as try to see the volume and location of contents.  Which
brings me to my questions.
 
I have notice a disproportionate number of ferrets suffering from adrenal
disease to have hairballs present in the stomach (or portions of hairballs
in the intestine).  My limited research: N = 187 ferrets; ferrets with
adrenal disease = 79; ferrets with identifiable hairballs 5 mm or larger =
52; ferrets with adrenal disease AND hairballs = 36 (I once might have made
mention of these data to some who read this list; if they look different
from these, it is because I redefined what I would call a hairball, causing
some numeric changes).  This makes sense to me; ferrets losing hair from
adrenal disease would have a high probability of ingesting more of it while
grooming.  Usually the hairballs are rather small, pea- or bean-sized or
smaller (but still 5 mm or larger), but I have recovered nine monsters of
the thumb-sized variety.  In one single case, I believe the cause of death
was due to the hairball.  It was a thumb-sized monster, trailing through
the pyloric valve into the duodenum.  A single 18 mm tear extended from the
pyloric region into the duodenum, and the abdomen was full of partially
clotted, reddish blood.  Food contents also filled the abdomen.  There was
no obvious signs of infection or inflammation.  The ferret was reported to
have died quickly, without warning.
 
So, the first question is, has anyone noticed a higher incidence of
hairballs in ferrets with adrenal disease?
 
One other thing I have noticed in adrenal ferrets is some degree of
osteoporosis, the degree of which appears to correlate to the severity
and length of the disease.  I notice it immediately when cataloging the
processed skeleton (which includes final cleaning, replacement of loose
teeth, numbering for identification, etc.).  I haven't yet taken
density/volume measurements, but it appears that from gross weight
measurements the loss in density could be as much as 15-40% (weight is a
very rough estimate and one I feel is unreliable, so these results
could/should be in error).  In terms of gross pathology, I have noticed
ferrets with extended adrenal disease (1.5 + years) to have microfractures
in the femoral and humeral heads, microfracturing, crushing or distortion
of the lumbar and thoracic vertebrae, extreme thinning of the ribs (on
sectioning, some appear hollow, with few trabeculae), and thinning of the
Os coxae, including the acetabular cup.  I have selected a number of these
bones for viewing under the SEM, but have yet found the financing to pay
for the gold spattering and machine time (which means I'll have to donate
my services to paying customers to earn free time when I can find the time
to do it).  Again, the loss of bone density is not surprising; I have
noticed it in several ferrets (and other species) who suffered from various
cancers, so I am making the possibly erroneous assumption adrenal cancers
act like calcium sinks.
 
So, the second question is, has anyone noticed a similar incidence of
decreased bone density in ferrets with adrenal disease?
 
If, by some quirk these data are true (my observations are a far cry from a
standardized research program), would it be appropriate to recommend weekly
doses of a hairball remedy, or add supplemental calcium to the diet for
ferrets suffering adrenal disease?  Could skeletal density be used as a
cheap and rapid screening agent for adrenal disease (x-rays or density
photometers)?
 
Discussion?  (Feel free to make me look silly; I learn best when making
mistakes.  I guarantee criticism will not bother me!).
 
 Bob C
 ------
 
Hi Bob,
 
I can tell there will be some hot ferret health discussions this weekend
( I have several vets coming here, too!).
 
[Re: hairballs]
 
Actually, I've been looking for them since you mentioned it awhile ago.
I have had my adrenal patients on some sort of hairball remedy, when they
aren't already.  Haven't noticed too much difference, but have had 2
adrenal surgeries out of the last 5 with multiple hairballs in the stomach.
These were all bean sized, 2 in one, 3 in the other.  The ferret with 3 had
been showing signs of gastric distress pre-op as well.
 
[Re: bone loss]
 
No, this I haven't noticed, but I'll review some xrays for you.
 
-Dr. Karen
 
DISCLAIMER:
This e-mail is provided for general informational purposes only.  It is in
no way intended as a replacement for a consultation with a qualified
licensed veterinarian.  If you are concerned about your pet's health, you
should seek the advice of your regular veterinarian as soon as possible.
 
 _______________________
 
 Subject: Re: Bob C: Question for *ALL* the Vets regarding Adrenal Disease
          (And anyone else with the knowledge)
 
Bob - Believe it or not, I didn't know the specifics of your thesis.  Very
interesting.
 
I'm afraid I won't be too helpful on the subject of hairballs - as a
consultant pathologist, it is something that I rarely see - no one needs
to get an opinion on a hairball - I get lots and lots of adrenals, but if
the hairballs are there, I'm lucky to get a mention of it in the clinical
history.  In fact, your numbers are somewhat of a surprise to me -
approximately 33% of your study animals have hairballs - far more than my
experience would show.  Your assessment makes logical sense, and perhaps
laxatone administration (or the previously mentioned idea of using a flea
comb to collect loose hairs, this time on adrenal cases, would be
cost-effective.
 
Regarding the loss of bone mass in adrenal ferrets - it is very difficult
to ascertain bone mass via radiographs in clinical practice due to the
great variation in radiograph quality.  This is magnified in my instance,
as I see radiographs from many practices - some overexposed, some
underexposed, etc.  It is difficult to quantitate bone density when
radiograph quality is a significant variable.  But perhaps in a single
practice where ferret radiographs were taken with a very stringent exposure
protocol.
 
It would be difficult to prove that bone loss is the direct result of
adrenal disease.  Hypoestrogenism (the opposite of what happens in ferrets)
acounts for osteoporosis in humans.  Most ferret adrenals do not secrete
appreciable amounts of cortisol, which might account for some bone loss,
if ferrets developed true Cushing's which they don't.
 
Other factors that need to be factored into bone loss in ferrets with
adrenal disease would be age, a sedentary lifestyle, and diminished
nutritional capacity associated with chronic inflammation of the GI tract,
etc.  Plus, as you mentioned, intercurrent diseases like heart disease and
systemic neoplasia may also result in catabolism of structural components,
so those are additional variables to consider.  A difficult proposition at
best!
 
I'll have to consider the part about the hairballs, though - sounds like
you are definitely onto something there.
 
With kindest regards,
Bruce Williams, DVM, DACVP
 
Join the Ferret Health List:
http://groups.yahoo.com/group/Ferret-Health-list
[Posted in FML issue 3350]