Inflammatory Bowel Disease (Lymphocytes and Plasma) in Dogs

Inflammatory bowel disease due to lymphocytes and plasma refers to inflammation of the gastrointestinal tract due to the infiltration of lymphocytes and plasma cells.  This is the most common cause of gastroenteritis (inflammation of the GI tract) in dogs.

The two most common symptoms of the disease are vomiting and diarrhoea.  Pain, weight loss, and lethargy can be seen in chronic cases.  Treatment involves dietary and medical management, however the prognosis for complete recovery is poor and long-term management is required.

Inflammatory bowel disease is a common form of gastroenteritis (inflammation of the stomach and intestines) due to the presence of abnormal cells.  Symptoms are gastrointestinal in nature including vomiting, diarrhoea, dehydration, and anorexia.

Symptoms are usually intermittent at first and will increase in prevalence as the disease progresses.  The most common symptom of inflammatory bowel disease due to lymphocytes and plasma in dogs is a large volume of dark watery diarrhoea.  Additional symptoms include:

• Vomiting
• Decrease in appetite
• Anorexia or weight loss
• Excessive hunger or increased appetite (less common)
• Increased desire to eat grass
• Gut sounds such as gurgling
• Dehydration
• Lethargy
• Abdominal pain

Types

Inflammatory bowel disease is characterised depending on the underlying cause of inflammation and the location of the gastrointestinal tract affected (e.g. the small intestines or large intestinal bowels).  Depending on the initiating cause and location affected, there will be differing symptoms and potential treatments.  Inflammatory bowel disease due to lymphocytes and plasma occurs predominantly in the stomach lining and small intestine.

The aetiology or definitive cause of inflammatory bowel disease is unknown.  It is thought to be associated with a deficient immune tolerance to bacterial antigens in the lumen of the gastrointestinal tract which contributes to the ease of infiltration by lymphocytes and plasma.  

Inflammatory bowel disease due to lymphocytes and plasma is most common in middle-aged dogs with the disease having a mean age of onset of approximately six years old.  There is thought to be some hereditary association.  Breed predispositions are speculated to include:

• German Shepherds
• Shar Peis 
• Yorkshire Terriers
• Cocker Spaniels

After obtaining a complete history and performing a thorough physical examination, the veterinary team will perform a serious of diagnostic tests to rule out differential diagnoses and make the definitive diagnosis of inflammatory bowel disease.  Differential diagnoses with similar symptoms include liver disease, intestinal bacterial overgrowth, lymphoma, gastrointestinal motility disorder, giardiasis, and food allergies. 

Diagnostic tests performed include fecal examination, abdominocentesis, diagnostic imaging (radiography and ultrasound), and gastrointestinal endoscopy and biopsy.

Faecal examination involves obtaining a faecal sample for flotation and culture tests.  It is an in-clinic test that is performed to rule out other causes of inflammation in the gastrointestinal tract such as intestinal parasites, giardiasis, or bacterial overgrowth.

Abdominocentesis is a surgical puncture of the abdomen using a needle to aspirate fluid.  The fluid contents are then assessed for colour, consistency, and contents.  Transudate fluid that has a low protein content and low specific gravity is indicative of inflammatory bowel disease.  The fluid will be analysed under a microscope to look for the presence of lymphocytes and plasma cells.

Abdominal imaging is performed to eliminate other causes as well as determine the spread of disease.  Ultrasonography is by far superior to radiography in order to assess abdominal organs, localise the spread of inflammation, and measure the thickness of the abdominal wall.

Gastrointestinal endoscopy and biopsy are the diagnostic tests of choice to definitively diagnose the cause of inflammatory bowel disease.  The dog is sedated while an endoscope is used to examine internal structures for luminal thickness, erosions, and mucosal lesions.  A small sample of the gastrointestinal lumen is collected as a biopsy and sent away to a histopathology laboratory for evaluation.  In some cases, veterinarians will obtain a surgical biopsy via an abdominal incision and excision of a tissue sample from the intestinal tract.  This is a surgical procedure which involves increased anaesthetic risk and can cause a delay in treatment initiation.

Treatment usually consists of a combination of dietary and medical management.  Ongoing therapy is required as symptoms will often reoccur.  The ideal case will be effectively controlled in the long-term with dietary management after medications have been tapered down.

Dietary management involves feeding a prescribed commercial or homemade diet that has been specifically formulated for the condition.  The ideal diet for inflammatory bowel disease due to lymphocytes and plasma is gluten-free with a highly digestible carbohydrate source, low in lactose and fat, and contains a newly introduced protein source.

Medical management involves the combination of several complementary drugs.  Drugs commonly used in the treatment of inflammatory bowel disease include corticosteroids (anti inflammatory steroids) and immunosuppressants.  Immunosuppressants reduce the efficacy of the immune system in order to decrease the inflammatory response.  The initial doses to control inflammation are high and are tapered down over subsequent weeks or months.  Other medications that may be involved in treatment include immunomodulators (drugs that modify the immune system to reduce inflammation), antibiotics, and gastric supplements.

Initial treatment to control symptoms and inflammation requires continual reassessment by the veterinarian in order to appropriately taper down drug dosages.  Once medications have been tapered down, ideal management involves long-term dietary control.

Dietary control involves a complete dietary change and regulated (often hypoallergenic) treats.  The diet should be highly digestible, gluten-free, low in lactose, and low in fat.  The diet should contain a protein source that the dog has not previously been exposed to.

The prognosis for a successful long-term management strategy is high, however a complete cure is unlikely.  Ongoing dietary and potential medical therapy will be necessary to prevent relapse.  Owner compliance is important. 

The treatment cost for inflammatory bowel disease is variable.  Cost will depend on the progression of disease and the time it takes for clinical remission to be seen with treatment.  Commercial diets can be expensive and range between $50 - $350 per month depending on the metabolic requirements of the individual dog.  Medication costs can range from $250 to $1500 depending on the combination of drugs used and length of therapy.  In severe cases where dehydration is prevalent, hospitalisation and rehydration with fluid therapy will be necessary.  This can average between $150 - $300.  As ongoing management is required, ongoing monthly costs can range between $50 - $300.