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Sunset Veterinary Clinic

Ask the Vet: Why Do Cats Throw Up?

Cat Sleeping on a Couch in the Sunlight

While it’s not rare, vomiting shouldn’t be a regular occurrence in cats. If anything, cat vomiting may be an early sign of something serious, so you shouldn’t overlook it. Here’s some helpful information about the types, causes and possible treatments for cat vomiting.

When humans vomit, something has gone wrong. This applies to cats as well. Owners should always discuss episodes of vomiting with their veterinarian. Solutions can often be found and hopefully the problem can be resolved.

Danel Grimmett, DVM

Types of Vomit

Cats vomit for many reasons, and the appearance of the vomit varies depending on the cause. Knowing the types of cat vomit and their common causes is important and will help you decide if you need to visit the vet clinic.


You may see blood if your cat has vomited several times in a row, as the resulting acid reflux can irritate their stomach and esophageal lining. Blood may also be present with ulcerations or a clotting abnormality due to certain diseases or toxins like rat poisoning. Blood in vomit can either look like normal blood or coffee grounds if it has been partially digested prior to being thrown up.


If your cat hasn’t eaten for a long time, it’s likely to vomit bile. This can happen when bile from the gallbladder backs up into the small intestines and stomach.

White Foam

White foam may result from inflammation of the lining of the stomach or small intestines, which can have a variety of possible causes.


Humans and animals alike suffer worm infestation, especially roundworms. If your sick cat vomits worms, you should see a pet vet to treat the issue appropriately.


Cats may vomit food after eating too much or too fast. It can also result from a nauseous stimulus, a food allergy, or a GI tract obstruction.


It’s not uncommon for cats to vomit hairballs when they have gastrointestinal upset. Cats are naturally able to move hair through their GI tract after they groom themselves. Any condition that disrupts normal GI tract function can lead to excess hair build up which then comes up when they vomit. Also, cats that are grooming themselves more often than normal due to skin disease can ingest more hair than normal and sometimes vomit hairballs. Some cats with long hair can struggle with excessive hair ingestion as well.


Mucus typically signifies a regurgitative process rather than vomiting. If you see mucus, check to confirm if your cat is vomiting or regurgitating.

Cats are amazing creatures and have almost supernatural abilities. One of these “magical” skills is covering up illness. They need their humans to look closely and pay attention to their needs. This is a tough job, but there are answers.

Danel Grimmett, DVM

Vomiting vs. Regurgitation

Vomiting is an active process involving forceful expulsion of the stomach and upper intestinal contents. It may be associated with drooling, retching and abdominal heaving. On the other hand, regurgitation is a passive expulsion of mouth, throat and esophageal contents. It happens quickly and is not accompanied by retching or heaving.

While vomit content and consistency are important, you should also note other factors like frequency and timing, as your veterinarian may ask about them.

What Vomit Colors Might Mean

Vomit color varies depending on the food or treats your cat eats, amongst other factors. Hence, color alone is not a reliable way to diagnose the cause of your cat’s vomiting. However, when combined with other factors, the color of your cat’s vomit becomes an essential part of diagnosing the underlying problem, be it a cat illness or otherwise. Here are common cat vomit colors and their possible meanings:

  • Yellow, orange or brown may signify the presence of partially digested food or bile in the stomach;

  • Red or pink may indicate the presence of blood or red dyes in the cat’s food or treats;

  • Clear or white may result from regurgitation of saliva, excessive water intake or vomiting on an empty stomach;

  • Green can occur due to the presence of bile or green food dyes;

  • Black or brown vomit that resembles coffee grounds may signify a bleeding process in the digestive tract.

Whatever color you find, it’s important to see a veterinarian to have the problem diagnosed accurately.

Different Reasons Why Cats Vomit

Like humans, cats vomit for many reasons, from relatively benign to more serious problems. Here are some of them:


You already know what hairballs are at this point. They are a relatively common finding in cat vomit and can be a sign of an underlying GI condition or skin disease.    


Gastroenteritis is an inflammation of the digestive tract lining. It may result from an infection with bacteria, viruses, parasites or medications, and it can even be caused by new foods.

Foreign Bodies or Obstructions

If your cat eats non-food materials, they may block and damage the GI tract and lead to vomiting. This is a serious situation requiring immediate veterinary attention.

Food Allergies and Inflammatory Bowel Disease

Allergies are not common in cats, but they can cause vomiting and even chronic diarrhea when present.

Systemic Illnesses

Chronic illnesses like kidney disease negatively affect cat health and can cause nausea and vomiting. You should see a vet to address the underlying condition.


Vomiting due to a parasitic infection often presents live worms in the vomit. Treating the illness usually resolves the vomiting.


Digestive tract cancers are relatively common in cats and may interfere with the normal digestive process, leading to vomiting. Cancers in other organs or tissues can also induce nausea, leading to vomiting.

Cat Vomit Prevention

You can prevent many causes of cat vomiting with these measures:

  • Ensure your cat eats more high-quality, balanced diets and fewer treats and table scraps;

  • Do not allow your cat to ingest non-food items;

  • Ask your vet about special diets if your cat is diagnosed with food allergies or inflammatory bowel disease;

  • Consider over-the-counter products for hairball vomiting.

When to Worry

Occasional hairballs are no cause for concern. However, you should get worried if:

  • Your cat is vomiting and not eating;

  • Other symptoms accompany vomiting;

  • Your cat is vomiting and sneezing;

  • Your cat is vomiting and constipated or having diarrhea;

  • Your cat is vomiting and drinking a lot;

  • Your cat is vomiting and pooping on the floor.

Cat Vomit Treatment

Just as there are many causes of vomiting, there are also many different treatments.

Vomiting due to cancer or systemic illnesses is resolved by treating the underlying condition. On the other hand, supportive care and antiemetic medications may be effective for milder causes of vomiting like hairballs or gastroenteritis. Sometimes, a diet change or a prescription diet will do the trick.

No matter the cause, the best route remains to visit the veterinarian for proper diagnoses and treatment.

Should I Call the Vet if My Cat Throws Up?

Apart from occasional hairballs, you should call your veterinarian right away if your cat vomits more than twice in a row, has other symptoms or has been diagnosed with an illness. If you’re unsure or concerned about your cat’s vomit, contact Sunset Veterinary Clinic with our online form or call us on (405) 844-2888.

Be honest with your veterinarian. Their job is tough enough. Full transparency is vital to caring for the needs of your pet. They cannot read your mind as well as the mind of your pet.

Danel Grimmett, DVM