What is it?
A spectrum of gastrointestinal disorders characterized by inflammation of the stomach and intestine (small and/or large), generally lasting more than 3 weeks in duration. It manifests itself in many different ways but may include any combination of anorexia, vomiting, weight loss, and diarrhea.
What causes it?
The current thinking is that the gut (gastrointestinal tract) has a persistent adverse reactivity to the bacterial flora that is a normal inhabitant. More specifically, two interdependent mechanisms involving the dog's local intestinal immune system response along with changes in motility or peristaltic contractions of the intestine (how it moves food downstream) are to blame for this condition.The human condition called "Irritable bowel syndrome" or IBS, in contrast to canine (and feline) IBD, is believed to share only the changes related to gastrointestinal motility.
NOTE: When your veterinarian encounters a pet with diarrhea, they first think about other causes that are more easily treated before pursuing a diagnosis of IBD. These may include food allergy, bacterial infection (pathogenic), worms/parasites, fungal infection, problems with the pancreas, problems with the lymphatic system, or in some cases - cancer.
How is it diagnosed?
After testing for and/or treating for other more common and treatable causes of gastrointestinal (Gl) upset, the steps to diagnose IBD may include abdominal ultrasound, endoscopy, and/or an abdominal exploratory surgery. Endoscopy and exploratory surgery are both methods used to obtain biopsies of the stomach and each section of the intestines. Sending biopsies into a board certified veterinary pathologist to analyze is the only way to definitively diagnose IBD. A pathologist will classify the disease by the type of white blood cell, or combination thereof, infiltrating the tissue. Next they identify which sections of intestine are affected and how severe (mild, moderate, severe) the changes are.
How is it treated?
Treatment may involve multiple oral medications and sometimes even weekly injections depending on the severity of the disease. The mainstay of treatment is aimed at suppressing the overactive immune system so that the inappropriate level of inflammation in the Gl tract is reduced to the point where the pet is no longer symptomatic for the disease. Any combination of the following categories of medication may be prescribed depending on many factors including but not limited to disease severity, labwork abnormalities, the pet's response to therapy, and the doctor's experience or comfort with certain protocols.
- Anti-inflammatory/immunosuppressives: Suppress the overactive intestinal immune response.
- Diet: Various types of diet and/or fiber supplementation may be attempted during treatment.
- Antibiotics: Aimed at managing any overgrowth of bacteria involved in stimulating the local immune system.
- Probiotics: These are living bacterial cultures similar to yoghurt but developed for dogs with various types of Gl disorders. More study is warranted in the use of these supplements.
- Anti-diarrheal agents: Sometimes used refractory cases unresponsive to other more common treatments.
- Exercise: Studies demonstrate exercise may aid in regulating normal colon motility.
Final thoughts:
Inflammatory bowel disease can be frustrating for pet owners, their veterinarians, and most importantly the pet! There is ongoing research on this disease that may one day reveal more about its cause and hopefully one day a cure.
CANINE INFLAMMATORY BOWEL DISEASE (IBD)
By Dr. Zach Anderson, DVM
MARCH, 2011
