CANINE Inflammatory Bowel Disease
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.
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 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 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.