Bilious Vomiting Syndrome

Many owners are worried when their dog occasionally throws up a somewhat foamy yellowish liquid, especially during the night or in the early morning.

The cause of the colour in dog vomit is due to the presence of bile. This is a bitter tasting yellowish fluid produced by the liver and stored in the gallbladder. This fluid is normally released by the gallbladder and directed to the small intestine in order to aid digestion and help with the absorption of fats.

Although this theory has not yet been scientifically proved, it is believed that a back flow of bile from the small intestine to the stomach irritates the mucous membrane and triggers the vomiting. Typically this happens when the stomach has been empty for a longer period of time, and often it is accompanied by a loud rumbling and an urge to eat grass.

There is no predisposition in age or breed. The condition can affect dogs of both sexes and all ages.

Although the condition is uncomfortable for the dog, it is rarely dangerous and the solution to the problem is often pretty simple and straightforward. All that may be needed is to feed the dog a small meal or snack before bed time. As a result of the ensuing gastro-intestinal activity, the back flow of bile will be prevented altogether or at least occur much less often. It also helps to split the daily food ration into two or even three portions and to serve the last meal not earlier than 8 p.m.

If, however, the problem persists and occurs more frequently, the vet should be consulted as there could be some serious underlying cause such as gallbladder infection or irritable bowel disease (IBD).

Thanks to Dr. Kamil Tomsa, Dipl. ECVIM-CA, Ennetseeklinik für Kleintiere AG, Hünenberg, Switzerland, for kind assistance with this article.