5 Reasons Why Your Dog Is Throwing Up Bile

Written by:

PetMD Editorial
Published: February 17, 2017


Reviewed and updated for accuracy on August, 11, 2020 by Susanne Felser, DVM

You’ve probably seen your dog scarf down something that is indigestible and chuck it right back up later. Intermittent instances of dog vomiting are generally fine and mostly not concerning from a health perspective.

The presence of bile, 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 is throwing up bile with any frequency, you should have them checked out right away.

Here are five of the most common reasons why dogs throw up bile:

Bilious Vomiting Syndrome

“Bile is a fluid produced in the liver and stored in the gallbladder,” says Dr. Rachel Barrack, DVM. “Once food is ingested, bile gets released into the small intestine and helps to break down food so the body can digest and utilize it appropriately.”

Bilious vomiting syndrome occurs when bile leaks into the stomach from the small intestine. This usually happens because a dog hasn’t eaten in a while or because they’ve consumed an abnormally large amount of fatty foods. It can also happen if the dog has eaten a lot of grass or drank a lot of water.

“Typically, patients affected by bilious vomiting benefit from readily digestible, low-fat, high-fiber diets,” Dr. Barrack says. You may also 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.

Gastrointestinal Diseases

When a dog is throwing up bile, it’s a sign 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 bile’s acidity can wear down the esophagus, it can lead to ulcerations if left unchecked. Breeds with sensitive stomachs that are predisposed to problems like this include Bulldog breeds, toy breeds, retrievers, and Poodles, says Dr. Taylor Truitt, DVM.


Endocrine disorders like pancreatitis can occur after a dog ingests highly fatty or oily foods, Dr. Truitt says. This causes inflammation of the pancreas, and in turn, bilious vomiting, along with intense abdominal pain and diarrhea.

Pancreatitis usually occurs three to five days after a dog eats fatty foods, but it can occur as early as 24 hours after. So you could see your dog throwing up bile between 24 and 48 hours after they ate the fatty food.

To help treat this, veterinarians will provide care to prevent against dehydration and electrolyte imbalances, Dr. Truitt says. During this time, treatment includes withholding food to allow the pancreas to rest.

Intestinal Blockages

Dr. Truitt states that toys, bones, and even large hairballs can create a blockage in the intestine. “These are emergencies and require immediate medical intervention,” she adds.

Regular vomiting turns into a dog throwing up yellow bile after their stomach has been emptied, but it’s ideal to address this problem before reaching this point. An extreme lack of energy and severe abdominal pain may indicate a blockage.

Surgery is the most common method for removal, Dr. Truitt says, but an endoscopic procedure can resolve some cases.


If your dog consumes something they’re allergic to, vomiting may occur, and bile may be present.

Often, this happens shortly after switching to a new food, and Dr. Truitt says that if you notice this, you should switch back to a food that you know works for your dog right away. “Common food offenders include beef, dairy, wheat, egg, chicken, corn, lamb, soy, pork, rabbit, and fish,” she says.

In other cases, a dog may become allergic to something they’ve eaten regularly for years. “Most pets develop food allergies within 1 to 5 years of age,” Dr. Truitt says, “but some pets move, and the change in the environment can trigger new allergies.”

In this case, a strict 12-week diet trial may be conducted to identify the offending protein. You could then work with a veterinary nutritionist to create a diet that removes the allergen without depriving your dog of the vitamins and nutrients needed to function at full strength.

Concerned about your dog vomiting? Learn more about when dog vomiting is an emergency.

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