26 Potential Reasons Why Your Cat Is Throwing Up

Updated September 17, 2021
A tired cat, feeling ill / sick

As a cat owner, you're likely familiar with the sound your feline friend makes right before they expel their dinner onto the floor. But if you've found yourself yelling "Not on the carpet!" more times than you'd like, you're ready to get to the bottom of it. There could be dozens of potential reasons why your cat is throwing up. It's important for you to understand what these are and when your cat's upset stomach warrants a trip to the vet.

Is Vomiting in Cats Normal?

Contrary to popular belief, vomiting in cats is not a natural feline behavior. This is a common misconception that many cat owners have, but if you were to vomit once a week, would you think this is "normal" for you? Probably not. Any time a cat throws up, there's a root cause behind it that should be addressed. This can be something as simple as overeating or eating too quickly, or it can be more complex, involving an endocrine disorder.

Why Cats Throw Up

The act of throwing up, known as emesis or vomiting, is a reflex action of the abdominal muscles and the central nervous system. A stimulus, such as ingested material or stomach inflammation, triggers the reflex action. An occasional bout of throwing up is typically not immediate cause for concern; however, you must watch your cat to make sure it does not continue and is not a symptom of something serious.

Cat Health: Vomiting vs. Regurgitation

Understanding the difference between cat vomiting and regurgitation is important if your cat is ill. Vomiting is a reflex involving the stomach, whereas regurgitation is generally associated with the esophagus.

When cats are about to vomit, they heave to throw up the contents of their stomach. There are usually a lot of abdominal contractions, movement, and effort involved in vomiting. When cats regurgitate, they usually lower their heads without warning and expel the food with very little effort. Regurgitated material is commonly undigested and may have a tubular shape, similar to the shape of the esophagus.

Vomiting and regurgitation can be classified as either acute, meaning it recently started, or chronic, defined as something that has been going on for longer than three months.

Causes of Cat Vomiting

Many experts categorize the causes of cat vomiting into two classifications: primary causes are gastric in origin, directly involving the stomach and digestive tract, and secondary causes are non-gastric, which are induced by diseases of other systems or organs. Dozens of reasons, conditions, and diseases exist that can cause vomiting in cats.

1. Hairballs

Swallowing a large amount of hair when grooming can cause an accumulation in a cat's stomach, known as a trichobezoar or hairball. There are numerous ways owners can help prevent hairballs, but once a cat has one, the only solution is to have them eliminate it. Large hairballs have the potential to obstruct the digestive tract and occasionally require surgery.

2. Food Allergies

If a cat is allergic to an ingredient in their diet -- most commonly the protein source -- they may exhibit stomach upset. Typically, cats with food allergies not only vomit but also have diarrhea, and some may develop itchy skin. You can discuss a novel protein or hypoallergenic hypoallergenic diet with your veterinarian if you feel that food allergies are the culprit.

3. Dietary Indiscretion

Cats who eat food or substances that do not agree with their digestive systems can develop acute gastritis. This food could be a new treat, spoiled food, grass, a bug, plant matter, or other material that could irritate the cat's gastrointestinal tract. Most of the time, gastritis from a dietary indiscretion resolves quickly on its own and you might never figure out what caused it in the first place.

4. Foreign Body

What goes in doesn't always come out. Foreign material can easily become stuck in a cat's stomach or upper intestine and cause an obstruction. If your cat enjoys playing with hair ties, yarn, or tiny toys, there's a possibility they could have swallowed it. These circumstances are considered medical emergencies and may need immediate surgery to remove the material. Strings are the biggest concern, as they can create linear foreign bodies, which can bunch up and even tear the intestines.

5. Overeating/Eating too Quickly

Just as you might feel sick if you ate too much or ate too quickly, this is a common cause of vomiting in cats. When a cat does this, the rapid stretching of their stomach triggers a reflex, and they regurgitate shortly after eating. The material is usually undigested. Feeding your cat smaller, more frequent meals or using a slow feeder can help.

6. Bacterial Infection

A number of bacterial infections in the gastrointestinal tract could lead to vomiting. Cats can contract common infections, such as salmonella, clostridia, or toxoplasmosis, from an infected rodent or undercooked meat. Diarrhea usually accompanies vomiting in these cases, and treatment with antibiotics and possible hospitalization are required.

7. Intestinal Parasites

Worms in a cat's gastrointestinal tract can lead to acute or chronic vomiting. You may see worms in your cat's vomit or stool, or none at all. Oral medication to kill the worms can resolve the issue. Your veterinarian may ask that you drop a stool sample off at the clinic to identify the type of intestinal parasites your cat may have.

8. Toxins

Toxic substances, such as antifreeze, lead, insecticides, flowers (namely, lilies), plants, and other chemicals, can promote acute or chronic vomiting. Many of these can damage not only the lining of the intestinal tract, but can also destroy other organs, including the kidneys and liver, or cause blood clotting issues. If you're worried that your cat has eaten something poisonous, it's important to seek veterinary care or call the Pet Poison Helpline for guidance.

British Purebred Gray Shorthair Cat Nibbles On Green Ficus Benjamin Plant In Pot

9. Intussusception

Intestinal intussusception (pronounced in-tuh-suh-SEP-shun) occurs when the intestines telescope into each other, which stops the flow of intestinal contents and causes acute vomiting. Intussusception involves one part of the intestine sliding inside another part of the intestine, sort of like what happens when you turn a sock halfway inside-out. This is not a common occurrence and typically has underlying causes such as worm infestations or bacterial or viral causes.

10. Megaesophagus

Megaesophagus is a condition where a cat's esophagus is continually dilated. Cats with this disorder cannot properly move food down to their stomachs; therefore, they frequently regurgitate immediately after eating. Most cats are born with this condition and are diagnosed as kittens, although adult cats can develop it in rare circumstances.

11. Hernia

A hiatal or diaphragmatic hernia occurs when the stomach is pushed through the diaphragm into the thoracic cavity. This is typically a congenital issue, or it can be caused by sudden trauma, such as if a cat is hit by a car. In addition to vomiting, your cat would likely exhibit labored breathing. Radiographs can diagnose this type of hernia, and surgical repair is typically the only way to treat it.

12. Abrupt Dietary Change

Gastrointestinal upset is common after a sudden change in diet. If you recently changed your cat's food, this could be the reason they're vomiting. Veterinarians recommend slowly transitioning from one diet to the other by gradually mixing the new diet in with the old, slowly increasing the percentage of the new diet you give your cat over several weeks.

13. Motion Sickness

Should the vomiting follow a trip in the car, motion sickness may be the cause. The foreign movement of the vehicle can make your cat so nauseous that they throw up. Other signs of nausea include drooling, lip licking, or stimulation of bowel movements. Your vet can prescribe a medication such as Cerenia that you can give before traveling to prevent motion sickness.

14. Inner Ear Infection

Although external ear infections are most commonly seen, it's possible for cats to develop diseases of the middle ear that can lead to nausea and vomiting. The reason for this is, inner ear infections disturb a cat's equilibrium. Other common signs associated with this deep ear infection include disorientation, head tilt, loss of balance, and deafness.

15. Constipation

When a cat becomes backed up with stool, they often feel sick and can vomit. You'll also likely notice a decrease in the volume of your cat's stool, hard or dry stool, and straining to defecate. Unfortunately, there can be underlying causes of constipation, such as kidney dysfunction or arthritis.

16. Kidney Disease

As the kidneys begin to lose function, they can no longer filter out toxins. This toxin buildup in the blood can lead to nausea and vomiting in cats. Chronic renal disease also commonly causes weight loss, increased thirst, and increased urine output in cats. Your veterinarian can perform blood work to determine if your cat's kidneys are functioning properly.

17. Liver Disease

Similarly, vomiting can be a sign of disfunction or cancer of the liver. Cats suffering from liver disease may have other symptoms, such as diarrhea, weight loss, inappetence, and jaundice. A blood panel or ultrasound can help your veterinarian understand what is happening inside your cat's body.

adult cat with liver failure with yellow ear

18. Pancreatitis

The pancreas is an organ that aids in digestion and hormone production. Inflammation of this organ is described as pancreatitis, which is a common illness in feline patients and can sometimes occur without any definitive cause. Cats with pancreatitis will often experience severe abdominal pain, lethargy, and a decrease appetite, in addition to vomiting.

19. Pyomtera

Female cats who have not been spayed are at risk of developing a pyometra or bacterial infection of the uterus. If a severe infection is present, a cat may understandably vomit, become lethargic, and stop eating. Pyometra is typically spurred by hormonal fluctuations, and can be resolved with surgical removal of the uterus.

20. Urinary Obstruction

Cats can experience an obstruction of their bladder due to crystals or sediment, commonly known as being "blocked." Blocked cats are unable to urinate and if the condition is left untreated, their bladder can burst. In addition to vomiting, a blocked cat may strain to urinate, howl in the litter box, appear agitated, and display severe discomfort. This condition is most common in male cats, given the abrupt angle of their urethra, and is considered a medical emergency.

21. Diabetes

Just like humans, cats can develop diabetes. Undiagnosed or poorly managed diabetic cats often have an increased appetite, increased thirst, and increased urination, yet rapidly lose weight. Vomiting may accompany these symptoms, as well. Diabetes is more common in overweight pets and can be managed with twice daily insulin injections, routine bloodwork, and possible diet change.

22. Feline Viruses

Viruses such as feline panleukopenia, feline leukemia virus (FeLV), feline infection peritonitis (FIP), and feline immunodeficiency virus (FIV) can cause affected cats to vomit. These diseases are infectious, so if your cat has been in contact with other cats, it is a good idea to have them tested.

23. Hyperthyroidism

Increased thyroid function or hyperthyroidism affects more than 10 percent of middle-aged and older cats. Together with vomiting, other clinical signs of hyperthyroidism include a disheveled hair coat, weight loss, hyperactivity, and increased appetite. Checking thyroid hormone levels can indicate whether this is the cause of your cat's vomiting. Medication or I-131 therapy can be used as treatment.

24. Heartworm

Cats are not ideal hosts for heartworms; however, they can become infected with them. A cat with heartworms may vomit, cough, breathe with increased effort, experience weight loss, or have a decreased appetite. Unfortunately, cats cannot be treated for heartworms as the medication used in dogs to kill the worms is toxic to cats. Prevention is the best way to protect your cat from this parasite.

25. Stomach and Intestinal Ulcers

When the lining of the stomach and digestive tract are compromised, ulcers can develop. This can happen for a number of reasons, including ingesting toxic plants, medications (typically combining medications that should not be given together, such as NSAIDs and steroids), trauma, or parasites. You may notice red, fresh blood in the vomit or stool, or black digested blood in either.

26. Cancer

Cancers of the stomach or upper intestinal tract can inevitably lead to vomiting. Other clinical signs include low energy and weight loss. Although this can be a devastating diagnosis, there are usually available options that make your cat comfortable for a short or extended period. Cats with small cell gastrointestinal lymphoma can live comfortably for months or even years on oral steroids.

When to Call the Veterinarian

If your cat has vomited and is still playing, eating, and showing no signs of physical discomfort, you likely don't have to rush to the vet. But be sure to keep an eye on your feline friend to make sure there are no other signs of a possible illness. If you note any of the following signs or symptoms, you should take your cat to the veterinarian immediately.

Vets examining X-ray
  • Your cat is a kitten, as they can become dehydrated and hypoglycemic very quickly as a result of vomiting.
  • Your cat throws up continuously for more than a few days.
  • Your cat vomits several times in an eight-hour time span.
  • You notice blood in the vomit. Fresh blood will be bright red or pink, and blood that has been digested looks like coffee grinds.
  • You see any objects or worms in the vomit.
  • Your cat is acting unusual in any way or appears depressed or lethargic.
  • Your cat has stopped eating or drinking.
  • If you know the cat has been near any poisonous materials such as antifreeze, poisonous plants, or insecticides.
  • If your cat is also exhibiting any of the following symptoms in addition to vomiting:
    • Diarrhea
    • Constipation
    • Weight loss
    • Dehydration

When Your Cat Tosses Their Cookies

Although your cat throwing up could be an unalarming occurrence with a benign cause, all cat owners must be aware that vomiting can also be a sign of a serious illness in a cat. Make an appointment with your veterinarian if you're concerned to rule out any underlying issues.

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26 Potential Reasons Why Your Cat Is Throwing Up