Written by Vet Evidence Based

Dog Throwing Up Bile – What’s Causing It?

Margarita Boyd
Written by: Dr. Margarita Boyd, BVSc MRCVS
Your dog just threw up bile out of nowhere, and you are wondering if this is something you should worry about or not. While throwing up bile in dogs might be completely irrelevant to your pup's health, vomiting too frequently is a sign that can indicate a variety of illnesses or diseases. Discover when you should bring your dog to the vet in this article!

You might have witnessed your dog throwing up bile before, or it might be something that you have heard other dog owners talk about.

Bile is a yellow liquid produced in the liver, to help aid digestion. It can come as quite a surprise the first time you see this frothy, yellow liquid being vomited up by your dog.

There are many reasons why your dog might vomit up some bile.

If it happens just once, and your dog seems otherwise happy and healthy, then it is most likely nothing to worry about. However, if your dog seems unwell or is frequently bringing up bile, then there may be an underlying condition causing him to vomit.

However, should you be worried about your dog throwing up bile? What can cause this problem? What should you do when your dog vomits bile?

In this article, we will discuss all the answers to these important questions and more.

What Exactly is Bile?

Bile is a liquid that is produced in the liver and then stored in the dog’s gall bladder. It can vary in color from a bright yellow to dark green and is often frothy in appearance.

The gall bladder is like a little bag that is attached to the liver and has a tiny tube which delivers the bile liquid to the small intestine.

It is delivered to the part of the small intestine which is very close to the exit of the stomach(1).

Why is Bile Important?

Bile has a number of important functions in the body including:

  • Helps the body digest fat
  • Helps the body absorb fat
  • Helps the body absorb vitamins A, D, E and K
  • Helps get rid of excess cholesterol
  • Helps eliminate waste products/toxins from the body
  • Neutralizes the acid entering the intestine from the stomach
  • Helps the intestines fight disease

Normally, when a dog eats, this stimulates the release of bile from the gall bladder into the start of the small intestine. Once there, the bile then carries out lots of important functions in the intestines.

What Causes Dogs to Vomit Bile?

You are more likely to see your dog throw up bile if his stomach is empty of food. Therefore, it can be the first thing your dog vomits up if his stomach is empty, or you may see bile after your dog has vomited all his food, then the bile appears.

If it is a once-off, maybe your dog ate some grass or something which mildly irritated his stomach?

Some dogs may even vomit bile if they are very hungry and have had an empty stomach for a long period of time. Other dogs may vomit bile if they are feeling stressed or anxious.

However, if your dog is showing signs of being unwell or is frequently throwing up bile there is often a more serious underlying cause, and you should make an appointment with your veterinarian.

There are many different reasons why your dog might throw up bile. Let’s take a closer look at the most common underlying reasons:

1. Eaten something bad

A common reason for your dog throwing up bile is if he ate something he wasn’t supposed to, which has mildly irritated his stomach.

It is a frequently encountered problem with curious dogs, who tend to put their nose (and mouth) into anything new. Common things include flowers or weeds from the garden or something from the trash.

Clinical signs may include one-off vomiting of bile, often with the offending trash item. The dog may lick his lips or drool a little if he feels nauseous.

Usually, after being sick the dog feels much better, but if the signs of sickness continue he will need to see a veterinarian.

2. Stress or anxiety

Dog throwing up bile can also be caused by stress or anxiety. Monitor when the episodes of bile vomiting are happening- is it when your dog goes somewhere new? Or during storms? Does he appear stressed before it happens?

You can try to reduce your dog’s anxiety or stress levels by providing him with a favorite toy or rug in these situations, or avoiding the stressful thing altogether which is making him anxious.

You may need help from a certified canine behaviorist if the anxiety is severe.

3. Bilious vomiting syndrome

Bilious vomiting syndrome (BVS) is one of the most common causes of throwing up bile in dogs. It causes a dog to have chronic vomiting of bile, often in the morning or late at night (2).

The exact cause is unknown, but it is thought to be associated with stomach and intestinal reflux, and when the stomach is empty for long periods of time.

The reflux of bile and fluid from the small intestine back into the stomach irritates the lining of the stomach, causing a condition known as gastritis.

Clinical signs often include vomiting bile in the early morning, nausea, decreased appetite, and weight loss. Treatment usually involves giving small feeds spread throughout the day, medications to reduce excess gastric acid and gastro-protectants.

4. Pancreatitis

The pancreas is a small flat organ that sits between the stomach and small intestine. It plays an important role in regulating the blood sugar level of the body and releases pancreatic fluid to help aid the digestion of food.

Pancreatitis is inflammation of the pancreas and is a painful and sometimes very severe disease(3). Most often in dogs, it is associated with eating fatty foods. Schnauzers are at higher risk of developing this disease.

Clinical signs may include vomiting bile, diarrhea, and intense abdominal pain.

Treatment varies depending on the severity of the signs. Mild cases may only require pain relief, anti-sickness medication, rest and bland food.

While some severe cases may require hospitalization with intensive treatment including intravenous fluids and medications.

5. Gastrointestinal diseases

Many things can cause gastrointestinal disease including parasitic infections, ulcers, bacterial infections, inflammatory bowel disease, or even certain cancers. These can all cause inflammation of the intestines, leading to vomiting of bile(4).

Clinical signs will vary depending on the cause and the severity of the disease but can include vomiting food or bile, diarrhea, inappetence, lethargy, and weight loss.

Again the treatment will depend on what is causing the gastrointestinal disease and you should seek veterinary help.

6. Intestinal obstruction

This is the cause of vomiting that most dog owners will worry about, especially if your dog is the type to pick up socks or children’s toys around the house.

Intestinal obstruction occurs when the dog eats an object it shouldn’t, which then becomes lodged somewhere along the intestinal tract.

The object blocks the passage of food and fluid along the intestines, leading to the dog feeling nauseous and sore(5).

Common clinical signs include vomiting bile, decreased appetite, and lethargy. The problem is diagnosed by x-ray or ultrasound and surgery is required to remove the foreign body from the intestines.

7. Food Allergies

Food allergies can cause inflammation of the intestinal tract and make your dog feel nausea leading to vomiting of bile. Other signs may include a skin rash often affecting the paws and ears, diarrhea and lethargy.

A controlled diet trial needs to be completed to diagnose this problem, which involves feeding a new, hypoallergenic diet for at least 8 weeks (with no treats or human food!) to check if the symptoms resolve. It is not a very common cause of vomiting bile in dogs.

Should You Take Your Dog to The Vet if He Vomits Bile?

When throwing up bile is too frequent, such as every day or twice a week, a visit to your veterinarian is necessary. If your dog is showing other signs of being unwell, such as reduced appetite, diarrhea or lethargy, then he should also definitely go to the vet clinic.

However, in some instances, your dog might seem happy and healthy but still be vomiting bile every once and a while, in this case, you could try making some adjustments to his diet or lifestyle to see if that helps.

If you’re wondering how to take care of your dog when he’s vomiting, take a look at this useful video:

Dog Vomiting Yellow

Sometimes it may happen for a dog to start throwing up yellow bile. This may happen from time to time, or as a more frequent occurrence. It may also appear foamy or not.

Yellow vomit is of very basic content: it consists of stomach acids and bile.

Stomach acids are created in the stomach lining to aid in digestion. Bile is a simple fluid that is produced by the liver and stored in the gallbladder.

To support digestion further, the bile enters the duodenum which is located just past the stomach.

So, when a dog vomits yellow bile, it may be a simple indicator that the stomach is empty. Gastric acids will easily irritate the stomach lining, which will lead to vomiting.

In some dogs, this may occur when they are really hungry. Other reasons may lead to your dog vomiting yellow. In some rare cases, it can just be a sign that your dog ate something yellow in color and isn’t capable of digesting it.

There are still differnet reasons why your dog might vomit yellow. In some cases, yellow vomit may be an indicator of the following:

  • Toxin exposure
  • Infectious disease
  • Liver disease
  • Gallbladder problems
  • Indigestion
  • GI inflammation
  • Pancreatitis
  • Indigestion

If your dog vomits yellow once, you shouldn’t be to worry about it. However, you should still check your dog for diarrhea, loss of appetite, and any behavioral change.

If you notice that something is really different, you might contact your veterinarian. Also, if you notice your dog vomiting more than once in a period of 24-hours, you might contact your veterinarian immediately.

Should You Change Your Dog’s Diet?

If your dog seems happy and generally healthy but is vomiting bile regularly, you could try checking and adjusting his diet:

  • Make sure you are feeding your dog a good quality complete and balanced dog food.
  • Two or three smaller feeds throughout the day are better than just one large feed.
  • Do not give your dog fatty foods such as meat trimmings or fried foods. These could be the root of the problem.
  • Do not give your dog too many dog treats- these can be high in hidden fat and salts.
  • Talk to your veterinarian or a canine nutritionist if you need advice about your dog’s diet.

What Feeding Times are Best?

If your dog is only receiving one large feed per day, this could be the cause of his bile problem. In this case, he spends the majority of the day with an empty stomach.

Increasing the frequency of feedings often really helps the problem.

You don’t need to increase the amount of food you are giving your dog; you just need to break it up into two or three smaller feeds. Some dogs will be better with two feeds per day, others may require three feeds spread throughout the day.

In dogs with bilious vomiting syndrome, it is often important to give a meal or small snack before your dog’s bedtime, especially if the bile vomiting is happening early in the morning.

Giving your dog food later in the evening will mean that the stomach is not empty for such a long period overnight, reducing the risk of reflux and gastric irritation.


Throwing up bile is actually a common problem in dogs.

Most of the time if it is just a once off, then it is nothing to worry about and is often caused by your dog eating some grass or something bad from the trash, or if your dog has had an empty stomach for a while.

If your dog seems happy and healthy you could try adjusting his diet and routine to see if that helps, for example, giving him three small meals throughout the day instead of one large one.

However, if your dog is showing signs of being unwell such as regular vomiting, diarrhea, lethargy or reduced appetite then you should bring him to the vet clinic.

There are many underlying conditions which can cause the regular vomiting of bile, that need to be ruled out by a veterinarian.