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.
Blood work 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 to 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 flare-ups.
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.
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