What to Do When Your Dog Is Vomiting Yellow Bile

Yellow bile vomit is something experienced by many middle-aged or senior dogs. Usually the dog is otherwise well, with a good appetite and normal poop — but the dog is vomiting yellow "foam" regularly, especially when they're hungry.

In the majority of dogs, this is down to a condition known as bilious vomiting syndrome.

So what is this condition, and is it serious?

Bilious Vomiting Syndrome: When Your Dog Is Vomiting Yellow Bile

When your dog is throwing up, the yellow foam or fluid you see is bile.

Bile is processed in the liver, stored in the gall bladder and squirted into the first part of the small intestine (where it joins the exit to the stomach).

Its job is to help the dog's digestive process. Once mixed with food, bile passes harmlessly down the intestine, where part of it is reabsorbed and recycled back to the liver.

OK, so if it's supposed to pass down the intestine, how does bile end up in the opposite direction in the stomach?

It seems likely that slackness in the valve at the exit of the stomach (the pylorus), allows bile to pass in the wrong direction.

This is common, but normally stomach contractions milk the bile back into the safety of the small intestine.

In bilious vomiting syndrome, when the stomach is inactive, those contractions are weaker or don’t happen.

Bile (also known as bile acids) is an irritant, so when it sits in contact with the stomach wall, this causes mild inflammation and irritation.

Hence, the dog with an empty stomach overnight may vomit up bile in the morning.

The next thing you may be wondering: How serious is it?

How Serious Is Bilious Vomiting Syndrome in Dogs?

In the vast majority of cases, bilious vomiting syndrome is not very serious.

I liken it to suffering from mild morning sickness. The dog feels nauseous and throws up, then is ready to eat and get on with their day.

However, it tends to happen in middle-aged or older dogs, which is also an age group at greater risk of other problems.

This means your veterinarian may check out more serious possibilities, just to be on the safe side. The sorts of problems to rule out include: A stomach ulcer Inflammatory bowel disease Giardia infection Stomach cancer or intestinal lymphoma A foreign body in the digestive tract To do this can mean blood tests, imaging the gut using ultrasound or endoscopy, and fecal analysis.

How to Help When Your Dog Is Vomiting Yellow Bile

For straightforward cases where more serious problems have been ruled out, the answer is often a simple change in feeding pattern.

For example, if your dog eats once or twice a day, then switching to several small meals could be the answer. This keeps the stomach active and working away for longer, so there’s less chance of bile sitting in the stomach.

At the very least, it can be helpful to give a carbohydrate-rich meal (such as boiled rice or pasta) 1–2 hours before bedtime.

Not only does this provide something slow to digest for the stomach to work away on, but the carbohydrate also does a great job of mopping up bile.

If your dog has gastritis

(inflammation of the stomach lining) due to long-term exposure to bile, then this change in feeding pattern may take a while for your dog's body to get used to. Occasionally, some dogs need a little extra help in the form of medication.

This guy cooks up some plain chicken and rice for his sick dog:

When Diet Change Doesn’t Work

If the problem continues, and your veterinarian hasn’t already ruled out other health problems, then now is a good time to do so. When these tests come back clear, the next step is to add in medication.

These medicines will coat the stomach lining and protect it, or reduce the amount of acid in the stomach.

Now, hold up! Before you reach for a human indigestion medication, know that some contain ingredients, such as aspirin, that can be dangerous to dogs. Never medicate a pet with human medicines without first checking with your vet.

Alternatively, your vet may prescribe a prokinetic, a drug that encourages the dog's stomach muscles to contract.

Final Thoughts on What to Do When a Dog Is Vomiting Yellow Bile

Happily, bilious vomiting syndrome is rarely serious and responds to simple changes.

So if your senior dog is a little sick each morning, they have this vet's permission to have an extra biscuit at bedtime. Nom nom nom.

References

• Ferguson, Leah, DVM, et al. "Bilious Vomiting Syndrome in Dogs: Retrospective Study of 20 Cases (2002-2012)." Journal of the American Animal Hospital Association 52, no. 3 (May–June 2016): 157–161. https://pubmed.ncbi.nlm.nih.gov/27008323/.
• Twedt, David C., DVM, DACVIM. "Don't Miss These Commonly Misdiagnosed Gastrointestinal Diseases." dvm360. Nov. 1, 2006. https://www.dvm360.com/view/cvc-highlights-dont-miss-these-commonly-misdiagnosed-gastrointestinal-diseases.

This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed and updated May 1, 2020.

If you have questions or concerns, call your vet, who is best equipped to ensure the health and well-being of your pet. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See additional information.