There are few things that get a dog parent out of bed faster than the unmistakable sound of your pup about to lose his dinner. Just like humans, dogs can vomit and have diarrhea from time to time. But if your dog's tummy issues don't resolve in a day or two, you might need to talk to your veterinarian about inflammatory bowel disease (IBD) in dogs and related conditions like colitis in dogs.

What Is IBD in Dogs?

IBD is a condition that involves inflammation of the walls of the gastrointestinal (GI) tract.  Sometimes this condition is also called chronic enteropathy and then subdivided into groups based on how the dog  responds to different treatments - food responsive, antibiotic responsive and steroid responsive.  For simplicity's sake, we are just going to stick to the term IBD for this article.

The majority of a dog's immune system resides in the GI tract, so imbalances here affect overall health and well-being. Over time, IBD can lead to weight loss, decreased muscle mass and a poor coat.

What Causes IBD in Dogs?

When food is consumed it travels down the esophagus and stops in the stomach, where it undergoes digestion and breaks down into a more liquid substance called chyme. The chyme then passes into the small intestine, where further digestion occurs.  The last stop in the GI tract is the large intestine, also called the colon. Here, bacteria break down the fiber in the food and water is absorbed. This process can be disrupted — at one or multiple points — by inflammation that alters the organs' ability to perform correctly. Inflammation in the stomach is called gastritis and usually results in vomiting. When the inflammation is in the small intestine it's classified as enteritis; in the colon, it's called colitis. The characteristics of your dog's diarrhea can help the vet determine if his GI issues are caused by enteritis or colitis, and can help in determining the proper treatment.

How Is IBD in Dogs Different From IBS?

The clinical signs of IBD can be similar to irritable bowel syndrome (IBS) in people, but the underlying cause is quite different. IBS in people is thought to occur as a result of abnormal movement of the muscle in the intestines. In IBD, the actual lining of the intestine is altered by inflammatory cells. The inflammation is an overreaction by the immune system — either to something your dog ate or from a malfunction of the immune system, called an autoimmune disease. This results in discomfort and interferes with the GI tract's ability to properly absorb nutrients.

How Does a Vet Diagnose IBD in Dogs?

To determine if your dog has IBD, thevet will first perform baseline blood work and fecal testing; these tests help assess your dog's overall health and rule out other medical conditions. An ultrasound or radiographs may also be necessary to image the organs of the abdomen. In some cases, your dog’s response to a therapeutic food may also help with the diagnosis.  For a definitive diagnosis, a biopsy of the intestinal tissue will need to be examined.