Background:
Inflammatory Bowel Disease (IBD) is a chronic inflammation anywhere
in the gastrointestinal tract, including the stomach, small
intestine and large intestine (colon). There are 5 forms of IBD;
lymphocytic-plasmacytic(most common), eosinophilic(relatively
uncommon), neutrophilic, granulomatous and histiocytic. These
classifications come from the type of cell that is causing the
inflammation. The cause of IBD is not known, and can probably be
attributed to a number of factors, including genetics and the immune
system.IBD is usually found
in younger dogs but can also affect middle-age dogs. There is no
specific breed predilection. The most common form of IBD is
lymphocytic-plasmacytic IBD (LPIBD). IBD is typically thought of as
an immune mediated disease and therefore treated with various
immunomodulating therapies. Current thoughts are that the GI tract
has been sensitized by some bacteria or food antigens that
determines the ongoing immune response. Complexes are formed from
antibodies against food antigens, bacteria or bacterial byproducts.
These antigen-antibody complexes (ABC) induce the release of
destructive chemicals into the area and tissue destruction results.
The destruction is indiscriminant. The quantity of ABC's produced
may influence the long-standing nature of the disease.
Clinical
Signs:
Symptoms are determined by the location and severity of the
inflammation, including chronic diarrhea, vomiting, bloody stools,
abdominal pain and weight loss. IBD affecting the stomach or upper
small intestine is frequently associated with chronic vomiting and
weight loss. IBD of the small intestine is associated with chronic
diarrhea, weight loss and infrequent vomiting.
Diagnosis:
Diagnosis can be difficult because the symptoms can mimic other
diseases. Positive diagnosis usually occurs after an endoscopic exam
with biopsy or by abdominal surgery. Biopsies are important to rule
out other causes such as dietary hypersensitivity, lymphoma,
histoplasmosis (a fungus), bacterial infection or overgrowth and
malassimilation problems.
Treatment:
Treatment depends on the type and severity of the disease. Some dogs
can be maintained with just a change in diet to one free of
additives and with a single protein source. Other dogs will need
some kind of medicine to control their illness. Anti-inflammatory
therapy involves immunosuppressive drugs, metronidazole, or
Salycilates. The mainstay of anti-inflammatory drugs are
corticosteroids. Prednisone and methylprednisolone are powerful
anti-inflammatory drugs that can produce impressive results. They
have minor short-term side-effects that include increased drinking,
eating and urinating. Long term, these drugs can cause Cushing's
disease if alternate day therapy can not be achieved for control of
IBD. Sulfasalazine is commonly used to control large bowel IBD. It
has no long-term side-effects, however it can cause a dry eye
syndrome and occasionally will cause salicylate toxicity.
Metronidazole is used because it is anti-inflammatory,
anti-protozoan and is a good antibacterial for the small bowel. The
only side-effect is vomiting. Other drugs that are being tried
include cyclosporine and eicosapentanoic acid, a fatty acid found in
fish oil. Eicosapentanoic acid (which is found in Derm Caps) is a
drug often used in veterinary medicine to decrease the inflammatory
response of inhaled allergies. IBD involves a great deal of patience
by the dog owner but most dogs will gain relief with some variation
of therapies. The disease is life-long and requires regular
attention.
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