Dr Liesel van der Merwe is a small animal medicine specialist. Send her your questions: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Dr Liesel van der Merwe

Vomiting is unpleasant and unfortunately dogs do it all the time. Most dogs are indiscriminate eating machines and unless you’re able to keep an eye on them 24/7, they’re probably going to eat something that they aren’t supposed to and bring it right back up later.

One-off episodes of vomiting are generally to be expected and normal and mostly not concerning from a health perspective. The presence of bile (gall/ gal), however, is a different story. This yellow-green substance is similarly unpleasant to clean up, but if it’s in your dog’s vomit – and especially if your dog starts vomiting bile with any frequency – you might want to have her checked out right away.

Bile is a fluid produced in the liver and stored in the gallbladder. Once food is eaten, it gets released into the small intestine and helps to break down food so the body can digest and utilize it.
Here are five of the most common reasons why dogs throw up bile:

Bilious vomiting syndrome occurs when bile leaks back into the stomach (refluxes) from the small intestine. This usually happens because a dog hasn’t eaten in a while or because he/she has consumed an abnormally large amount of fatty foods.

It can also happen if the dog has eaten a lot of grass or drunk a lot of water. Patients affected by bilious vomiting benefit from readily digestible, low-fat, high-fiber diets. You may want to consider smaller, more frequent meals for your dog, especially if the bilious vomiting occurs first thing in the morning, after a long period without eating.

Bile stained vomiting is a symptom of a number of conditions that affect the digestive system, including inflammatory disease, ulcers, parasite infections and certain cancers. In each of these cases, the underlying condition needs to be diagnosed and treated by a veterinarian to relieve the vomiting.

Because acidity of the gastric acid and corrosiveness of the bile can damage the lining of the intestinal tract, it can cause oesophagitis and ulcerations if left unchecked. 

Inflammation of the pancreas can be caused by eating fatty food. Pancreatitis in turn causes nausea, anorexia, bilious vomiting, along with intense stomach pain and diarrhoea. Pancreatitis usually occurs two to three days after eating fatty foods, but can occur as early as 24 hours after. Fat, female, middle-aged small breed dogs are predisposed, specifically miniature schnauzers.

Treatment is mainly supportive. Vets will provide care to prevent against dehydration and electrolyte imbalances and pain control. Once affected, the dog will always be sensitive to fatty diets and will relapse if fed inappropriate foods.

Foreign bodies also cause vomiting, usually not accompanied with any diarrhoea. Toys, bones, cloths and clothing as well as maize cobs might create a blockage in the intestine. These are emergencies and require immediate medical intervention. Metal and bone objects are easily seen on X-rays whereas cloth, plastic and soft toys are often only seen by the gas build-up caused by the obstruction. These will need an abdominal scan to confirm.

Severe non-productive vomiting and salivation can also be the first sign of gastric dilation volvulus syndrome, where a full stomach twists around the entry (oesophagus) and exit (duodenum) parts of the gut. The stomach then swells up with air and fermentation. This is a life-threatening condition as it can result in shock and circulatory failure.

Surgery is the most common method for removal, but an endoscopic procedure can resolve some cases if the foreign body is small and still in the stomach.

Dietary intolerance occurs if your dog consumes something he/she is allergic to. Vomiting may occur and bile may be present. Often, this occurs soon after changing to a new food. Common food offenders include beef, dairy, wheat, egg, chicken, corn, lamb, soy, pork, rabbit and fish.  

In other cases, a dog may become allergic to something they’ve eaten regularly for years. Most pets develop food allergies within one to five years of age, but some pets move, and the change in the environment can trigger new allergies.

In this case, a strict 12-week diet trial (novel protein or hypoallergenic hydrolysed diet) may be conducted to identify the offending protein. 

So, any recurrent vomiting, non-resolving acute vomiting or severe anxious attempts at vomiting with abdominal discomfort are often due to a more serious illness than “just something he ate”.