Diagnosis
If your dog has a history of frequent diarrhea and/or vomiting and you suspect that he may have IBD, your veterinarian should start by performing a thorough physical exam on your pet. In most cases, dogs with IBD will not present with any obvious problems upon examination besides potentially being thin. If the disease is very severe, your vet may actually be able to physically feel the thickened intestines via palpation. The next step would be to perform blood work on your dog. Your veterinarian will check to see if there is an increase in any of the enzymes from the organs which surround the intestines, and also to see if there is an increase certain cells of the immune system.
Veterinarians may also choose to x-ray your dog to rule out the possibility of a tumour or other obstruction in the intestinal tract. It may also be possible to visualize a thickened intestine on the x-ray. Each of these tests is fairly non-invasive, and it is possible that your veterinarian may feel confident in making a diagnosis of IBD based on these findings alone. However, the only way your veterinarian can diagnose this disease with absolute certainty is to perform a biopsy on your dog. This will involve taking a small tissue sample from the gut which is analyzed in the lab. While this procedure is considered to be invasive, it can help to put minds at ease by providing you with a definitive diagnosis.
Causes
The causes of IBD are not well understood. Usually, a cause is not found. The basic theory is that "something" is leading to a chronic stimulus of inflammation. This could be an allergy against a food protein, the continuing presence of a parasite, inflammatory products produced by the normal bacteria living in the intestine or there may be an underlying problem with the immune system in affected individuals. Obviously, there may be different causes in different individuals or a combination of the possibilities listed working together. Most of the time an extensive search for the underlying cause is not made.
Treatment
Most dogs with true IBD require medication in addition to dietary management to have complete resolution of symptoms. If dietary management alone results in complete improvement a diagnosis of IBD caused by an adverse reaction to food is made.
Diet
Highly digestible diets are usually recommended for dogs with IBD because nutrients from these diets are more completely absorbed and the amount of diarrhea will be minimized. Diets that contain a single protein source never previously eaten and a carbohydrate source that is unlikely to be antigenic (such as potato) may also be recommended. Commercial products are available or your veterinarian can advise you on a homemade dog food recipe. An appropriate diet must be fed for eight to twelve weeks before a positive affect may be seen.
Fiber supplementation is recommended for IBD that affects the colon. Dietary fiber improves stool consistency and produces fatty acids that nourish the colon and discourage the growth of harmful bacteria.
Medication
Corticosteroids (aka steroids, cortisone, prednisone) are the mainstay of therapy for IBD. Corticosteroids inhibit the inflammatory process and reduce the inflammation within the intestine. As steroids have potentially severe side effects, the goal of therapy is to gradually adjust the dose to the lowest possible amount that controls symptoms. Over time, many dogs can be weaned off steroids completely and be maintained on diet alone.
There are several other anti-inflammatory medications available and you should ask your veterinarian if any of them are right for your dog. Metronidazole is an antibiotic that helps restore the normal balance of intestinal bacteria and also has anti-inflammatory properties. The beneficial effects of metronidazole can sometimes reduce the dosage of steroids that are needed. Dogs with severe cases of IBD often need more aggressive anti-inflammatory therapy. Azathioprine, chlorambucil and cyclosporine are examples of drugs that reduce inflammation by suppressing the immune system.
Some dogs benefit from antacid, anti-nausea or anti-diarrheal therapy. Your veterinarian can advise if any of these are right for your dog.
Prognosis
IBD can be controlled, but not cured. All patients with IBD will require a strict diet and possibly anti-inflammatory medication to manage their disease. Most dogs with IBD do well for many years while others require alterations in therapy every few months to treat flare-ups and recurrent symptoms. Unfortunately, a few dogs will fail to respond to treatment and some severe forms of IBD can progress to intestinal cancer.
