Eosinophilic enteritis is a sporadic disease of ferrets which is most
often seen in young male ferrets.  It is a disease that was discovered
about ten years ago, and unfortunately, we know little more about it today
that we did back then.  Eosinophilic enteritis is a variant of the complex
of diseases known cumulatively as "inflammatory bowel disease" in ferrets,
but whose appearance is characteristic enough to have earned it a name of
its own.
 
Eosinophilic enteritis is actually a misnomer, as the lesions in this
disease extend far beyond the intestinal tract, and can be seen in any
abdominal organ (I commonly see it in liver, mesenteric lymph nodes, and
pancreas), and has even been documented in the thorax as well.
 
Eosinophilis are a type of white blood cell that moderates allergic and
antiparasitic reactions in the normal animal.  For this reason, we have
long believed that it arises from a food allergy or parasitic infection,
however, there is no real evidence to back this up.
 
The problem with EE is that eosinophils are filled with some very
destructive compounds which they normally use against parasites.  In this
disease, large numbers of eosinophils degranulate in the tissue, causing
intense tissue damage.  It is almost like a chain reaction, devitalizing
tissue in many organs of the body.
 
The diagnosis of EE is somewhat difficult - because of the range of
tissues that it affects, the clinical signs are often vague.  If the
intestine is affected, the main sign is diarrhea, anorexia, and weight
loss.  If the disease is more widespread in the abdomen, you may also see
pain on abdominal palpation.
 
Bloodwork may show elevated levels of eosinophils, and any significant
increase in eosinophils in an animal with GI signs should make the prudent
practitioner think of EE as a possibility.  Definitive diagnosis, however,
is made by biopsy of affected tissue during exploratory laparotomy.  Note
to vets: while it may be difficult to identify inflamed areas in the
abdomen in cases of EE, always biopsy the mesenteric lymph node as part of
your sampling - it very commonly exhibits large infiltrates of eosinophils
in affected animals.
 
As we don't really know the cause of this disease, treatment revolves
around minimizing the damage done to the body's tissues by the
eosinophils.  Prednisone helps to stabilize the membranes of these cells,
keeping them from degranulating as easily, and it also decreases their
ability to congregate in large numbers.  However, it can't work miracles,
and often the disease is well advanced before we even know an animal has
EE, and damage in the GI tract or other parts of the abdomen is too
advanced for a good prognosis.  If we can get a handle on the disease with
prednisone, treatment is generally life- long - removal of the prednisone
results in a relapse.  The key is to find the lowest dose that controls
the signs and maintain on that.
 
Another important part of treating these animals is do change the
diet.  Most animals will benefit by a switch from traditional chicken-
based-protein foods.  Foods that have been used to good effect are
turkey-and barley based foods or Hill's z/d, a prescription food in which
the chicken protein is hydrolyzed so that the body does not recognize it
as chicken.  Initially, turkey based baby food will help those in acute
phases of the disease, or during flareups.
 
Years ago, I gave EE cases a poor prognosis.  Today, the outlook for these
animals is much better, and most can live to an old age.
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3691]