There are few things that get a dog parent out of bed faster than the unmistakable sound of your dog about to throw up. Just like humans, dogs can vomit and have diarrhoea 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, we are just going to stick to the term IBD for this article.

Signs that your dog may have IBD include frequent vomiting, decreased appetite, weight loss, loose stool, frequent defecation, or liquid or bloody diarrhoea. Over time, IBD can lead to weight loss, decreased muscle mass and a poor coat. If you notice any of these signs, you should make an appointment with your dog's vet.

What Is Causing the GI Upset?

To understand the cause of GI upset associated with IBD, it is important to understand how food is broken down and absorbed by the body. When food is consumed, it travels down the oesophagus 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 most of the digestion and absorption of nutrients into the body occurs. The last stop in the GI tract is the large intestine, also called the colon. Here, bacteria break down the fibre in the food and water is absorbed. This process can be disrupted — at one or multiple points in the GI tract — by inflammation that alters the organs' ability to perform correctly .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.  

 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 diarrhoea can help the vet determine if the GI issues are caused by enteritis, colitis or both, 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.