What is inflammatory bowel disease?
Inflammatory bowel disease (IBD) is not a specific disease. Rather, it is a specific reaction that the stomach or intestines have to chronic irritation.
What are the clinical signs of IBD?
If the stomach is involved, your dog will have chronic vomiting. If the intestines are involved, chronic diarrhea will occur. This is the most common form. In some dogs, both parts of the digestive tract are involved, so both vomiting and diarrhea occur. If the disease occurs for several weeks to months, weight loss and poor appetite are common.
When does IBD generally occur?
IBD is most common in middle-aged to older dogs, but it can occur in younger dogs as well.
How is IBD diagnosed?
The chronic irritation that causes IBD stimulates the body to send cells from the immune system to the affected area. The most commonly found cells are lymphocytes and plasmacytes. Occasionally, eosinophils and neutrophils will be found. Thus, the disease is diagnosed when these cells are identified in abnormal levels in the tissue. A pathologist is responsible for this part of the diagnosis; his/her report usually calls the disease lymphoplasmacytic gastritis (relating to the stomach) or lymphoplasmacytic colitis (relating to the colon).
In order to obtain these cells, a biopsy is required. In most cases, an endoscope is passed into the dog’s stomach or colon (while the dog is under anesthesia). A tiny biopsy instrument is passed through the endoscope and used to take small samples of the lining (mucosa) of the affected organ.
Is this the only test required for diagnosis?
The tissue reaction that occurs in the stomach or colon is diagnosed with a biopsy. However, determining what causes the tissue reaction to occur requires further testing. Tests or treatments should be performed to rule out stomach and intestinal parasites, cancer and infections. Diseases such as diabetes are also considered. In addition, diseases of the kidney, liver and pancreas should also be ruled out.
How is IBD treated?
The ideal way to treat this problem is to diagnose the underlying disease that is causing the reaction. Sometimes the above mentioned tests will do that and sometimes a cause cannot be found. In the latter situation, the disease is called idiopathic. That means that a disease is present, but there is no known cause. Many cases of IBD are considered idiopathic.
Some dogs with IBD respond to a change in diet. This is done in two ways. First, a food is chosen that contains a protein source that the dog has never had, such as duck or fish. If that is not effective, a high-fiber diet is tried. Unfortunately, a true food trial requires that the test diet be fed exclusively for four to six weeks. If dietary therapy is not successful or feasible, drugs are used to suppress the inflammatory reaction.
Do corticosteroids cause side effects in dogs?
Corticosteroids, like prednisolone, are notorious for causing a variety of side effects in humans. However, this is rarely the case in dogs.
To minimize any possible adverse effects, our goal is to use the lowest dose that is effective and to give it on an every other day schedule. It will be necessary to begin therapy with a rather high dose, but once response occurs, the dose is tapered to a minimal level.
Does this mean that I will be medicating my dog for the rest of his/her life?
Long-term therapy is required for many dogs. Generally, a dog is treated for a few months before prednisolone is discontinued to see if it is still needed. If the signs of vomiting or diarrhea recur, medication is resumed.
Are other anti-inflammatory drugs used?
Prednisolone is the most effective anti-inflammatory drug with the least side effects. However, it is not effective in all dogs. Sometimes a stronger drug is used initially to gain control of the disease. Then, prednisolone is tried again as a maintenance drug.
Could stomach infections be a cause of IBD?
Some spiral-shaped bacteria can cause vomiting in dogs. The most common are helicobacter pylori, which have been shown to be the cause of disease (including stomach ulcers) in humans and are also pathogens in dogs. However, they are also found in many normal dogs and humans. Therefore, finding spiral-shaped bacteria on biopsy is not always meaningful. It is considered a pathogen only if an associated inflammation is in the stomach mucosa.
What is the prognosis?
If a response occurs to diet change, the dog can be maintained on a this diet for the rest of his/her life (as long as it is balanced). If the dog responds to medication for stomach bacteria, a good prognosis is justified. If response occurs to corticosteroids, the long-term prognosis is also good if administration of the drug is feasible. However, if there is no response to diet or corticosteroids, the prognosis is more guarded. At that point, further testing is suggested to see if an underlying disease can be found.
See Inflammatory Bowel Disease in Cats