Why Is My Cat Throwing Up Yellow Liquid?

Published Dec. 22, 2023
An orange cat sits on a hardwood floor.

There are several reasons why your cat may vomit. Vomiting means a cat is forcefully removing the contents of his stomach out of his mouth. Cats can also vomit a wide variety of other substances, including  yellow liquid, hairballs, blood, or random objects they’ve ingested.

Any time a cat vomits may be cause for concern, especially if the vomiting is accompanied by other troublesome symptoms such as reduced appetite or lethargy.

Let’s look at the most common reasons why cats throw up yellow liquid, for example, and when you should bring your cat to their veterinarian. 

Your Cat Is Throwing up Yellow Liquid. What’s Happening?

If your cat is throwing up yellow liquid, it’s most commonly a substance called bile. Bile is a thin, yellow-colored fluid produced by the liver and stored in the gall bladder. Its yellow color is due to its bilirubin, which is a substance produced when the liver breaks down old red blood cells.  

Bile is normally released during meals to help digest food. If the stomach is empty for long periods of time, bile can build up and cause irritation of the stomach lining, which leads to vomiting up the yellow liquid.

Sometimes vomit with yellow liquid can also be a sign that your cat chewed on or ingested something yellow that he shouldn’t have. This could be a type of food or an object from around your home, such as foods with yellow dyes in them or a yellow marker.

When a cat vomits bile, it’s typically because he has gone too long without eating.

Typically, a cat vomiting yellow bile is not considered a medical emergency—as long as your cat is otherwise behaving normally and has no additional symptoms.

However, vomiting yellow liquid can be a medical emergency if there’s an underlying health issue, your cat ate something they shouldn’t have, or there’s an intestinal blockage. These instances are typically characterized by other symptoms, such as lethargy, decreased appetite, and abdominal pain, and should be addressed by a veterinarian immediately.

If your cat throws up yellow liquid and you are not sure why, bring him to the veterinarian immediately. If your cat is throwing up yellow liquid and there are no additional symptoms such as lethargy and abdominal pain, connect with a Chewy veterinarian through Connect with a Vet to determine if symptoms are serious enough to take your cat to the vet.

Why Cats Throw up Yellow Liquid

There are various reasons why cats may throw up yellow liquid. These range from minor concerns to serious health conditions. If your cat is ever throwing up yellow liquid, it’s important to speak with your veterinarian about potential causes and whether or not treatment is necessary.

Let’s discuss a few common reasons why your cat may throw up yellow liquid.

Your Cat Has a Hairball

Hairballs are common in cats, especially those with long fur.

Because a cat’s tongue has small spines on it, loose hairs are removed from the fur and swallowed during grooming. Hair is not digested, so it may collect in the stomach if it does not pass through the intestines and into a cat’s stool.

Over time, a clump of fur can form and cause irritation in the stomach. This discomfort results in the cat vomiting up the hairball, which is often mixed with a small amount of bile.

Throwing up a hairball every once in a while—such as once a week—is usually not cause for concern.

However, if your cat is throwing up hairballs more frequently, it could indicate an underlying problem. Speaking with a veterinarian about prevention of hairballs is important. Prescription diets and other oral medications may be recommended to help reduce their frequency.

If your cat is throwing up bile, is not eating, and is losing weight, it could be a sign that a hairball has caused a blockage in the intestines. This is a serious cause for concern and should be dealt with by a veterinarian immediately.

Your Cat Doesn’t Have Anything in Their Stomach

When a cat goes too long without eating, bile buildup can cause inflammation within the stomach and subsequent vomiting.

This can occur if they skip meals, are on a fast before a surgical procedure, or have bilious vomiting syndrome (BVS). To prevent this, ensure that your cat is eating meals at regular intervals. Cats with particularly sensitive stomachs may require smaller meals at more frequent intervals.

Your Cat Has an Underlying Health Condition

Sometimes a cat vomiting yellow liquid is the first sign of an underlying disease that requires treatment by a veterinarian.

Some health conditions that may result in your cat throwing up yellow liquid:

  • Liver or gallbladder disease can result in cats throwing up yellow liquid. This can be due to inflammation, infection, or blockage of the bile ducts. Cats may also experience reduced appetite, yellowing of the skin and eyes, and weight loss.

  • Pancreatitis refers to inflammation of the pancreas, an organ that helps regulate blood sugar and digest food. When the pancreas is inflamed, it can obstruct the bile duct through which bile normally travels. When this occurs, cats may vomit up yellow liquid. Affected cats may also experience diarrhea, abdominal pain, and lethargy.  

  • Gastritis and enteritis refer to inflammation of the stomach and intestines, respectively. Many cats experience diarrhea and reduced appetite in addition to throwing up bile.

  • When cats eat things that they shouldn’t, it can lead to them vomiting yellow liquid. This is usually due to a cat eating a substance containing yellow pigment. However, if a cat eats an object too big to pass through the digestive tract, an obstruction can occur. In this case, the cat will feel ill and be unwilling to eat, which can lead to vomiting yellow liquid.

  • Diabetes is a common condition in older cats, and affected cats often vomit bile due to high  blood sugar levels. They usually drink and urinate more frequently and experience weight loss as well.

  • Kidney disease frequently affects senior cats, which causes toxins to build up in the bloodstream. Affected cats feel ill and have reduced appetites. The combination of having an empty stomach, along with increased acid production in the stomach of cats with this condition, can result in vomiting of bile.

Less commonly, hiatal hernias and acid reflux can result in cats throwing up yellow liquid.

Sometimes a cat vomiting yellow liquid is the first sign of an underlying disease that requires treatment by a veterinarian.

When To Call Your Vet

Pet parents should call their veterinarian if their cat vomits yellow liquid and its cause is unknown.

For example, if your cat throws up bile but you remember that he missed his dinner the night before and is otherwise acting normally, the vomiting episode was most likely due to an empty stomach.

However, if your cat is experiencing other symptoms along with vomiting bile, such as reduced appetite, lethargy, or abdominal pain, there may be an underlying health condition that needs to be addressed.

When in doubt, it’s always best to call your veterinarian with any concerns about your cat’s health.

Featured Image: Konstantin Aksenov/iStock / Getty Images Plus via Getty Images

Brittany Kleszynski, DVM


Brittany Kleszynski, DVM


Dr. Brittany Kleszynski is a veterinarian and freelance medical writer who specializes in creating meaningful content that engages readers...

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