Why Does My Cat Keep Throwing Up? A Veterinarian’s Perspective

grey tabby outside, vomiting up grass, used to illustrate one of the reasons "why does my cat keep throwing up"

It’s 3 AM, and you wake up to that dreaded sound – your cat is throwing up again. As a cat parent, it’s worrying when your fur baby can’t seem to keep their food down. 

You’re not alone in this struggle. Many cat owners find themselves googling “why does my cat keep throwing up” in the middle of the night, desperate for answers.

From pesky hairballs to potentially serious health issues, there could be a variety of reasons behind your cat’s upset stomach. Read on if you want to learn the most common causes of cat vomiting and discover tips on how to help your cat feel better.

Why Does My Cat Keep Throwing Up?

There are several reasons why your cat may be throwing up, ranging from simple hairballs to more serious conditions like kidney disease. Let’s have a look at some of the more common causes of cat vomiting.


Hairballs are a very common cause for a cat to vomit. As hair builds up in the stomach, it irritates the stomach, inducing vomiting. Most of the time, it is not significant. 

However, if your cat continuously gets hairballs, it can lead to more serious problems. Too much hair in their stomach that cannot pass it through their stool may cause an obstruction inside their intestines.

grey and white cat photographed in the middle of vomiting up a hairball

Dietary Changes

Cats with sensitive stomachs are prone to vomiting in reaction to dietary changes. This sensitivity can be triggered by switching to a new brand or type of food, introducing new treats, or even minor alterations in their regular diet. 

Sudden changes in diet can cause an upset tummy in many cats, even if they don’t normally have a sensitive stomach. New foods can disrupt the delicate balance of the gastrointestinal tract in these cats, leading to vomiting as their system reacts to the unfamiliar ingredients or composition. 

Intestinal Parasites

Worms can cause vomiting in cats by irritating the lining of the gastrointestinal tract or by obstructing the intestines. When worms infest the stomach or intestines, they can cause inflammation, which triggers vomiting as the body’s natural response to expel the parasites. 

In some cases, severe infestations can create blockages in the intestines, leading to vomiting as the cat’s body tries to rid itself of the obstruction

Inflammatory Bowel Disease

In cats with inflammatory bowel disease (IBD), the immune system reacts abnormally to certain substances in the diet or gut bacteria, leading to chronic inflammation of the intestinal lining. This inflammation disrupts normal digestion and absorption of nutrients, causing vomiting, diarrhea, weight loss, and decreased appetite. 

The vomiting in cats with IBD is often a result of the underlying inflammation and gastrointestinal upset, and it may occur intermittently or persistently depending on the severity of the condition.

Kidney and Liver Disease

Kidney and liver disease can cause vomiting in cats due to their impact on the body’s metabolic processes and toxin elimination. In both conditions, the impaired function of these vital organs leads to a buildup of waste products and toxins in the bloodstream. 

This accumulation can trigger nausea and vomiting. Additionally, kidney and liver disease can cause electrolyte imbalances and disturbances in fluid balance, further contributing to gastrointestinal upset and vomiting. 

grey tabby cat looking sick and sad

Other Causes Of Vomiting in Cats

Other causes of vomiting in cats include:

  1. Pancreatitis: Inflammation of the pancreas, which can result from dietary indiscretion, infections, or certain medications.
  2. Gastrointestinal Obstruction: Blockages in the stomach or intestines, commonly caused by ingesting foreign objects, hairballs, or tumors.
  3. Hyperthyroidism: Overactive thyroid glands can lead to increased metabolism and gastrointestinal disturbances, including vomiting.
  4. Feline Viral Infections: Viral infections such as feline panleukopenia virus (FPV) or feline leukemia virus (FeLV) can cause gastrointestinal symptoms, including vomiting.
  5. Food Allergies or Intolerances: Cats may develop allergic reactions or intolerances to certain ingredients in their food, leading to vomiting as a symptom.
  6. Stress or Anxiety: Emotional stress or changes in the cat’s environment can sometimes lead to vomiting.
  7. Systemic Diseases: Various systemic conditions such as diabetes mellitus, hypercalcemia, adrenal disease or certain types of cancers can cause vomiting as a secondary symptom.
  8. Toxins

Key Takeway: Accidental ingestion of toxic substances such as plants, human medications, or household chemicals is an EMERGENCY. If you suspect your cat has got into something poisonous, call the ASPCA Poison Control Hotline at 866-426-4435 or the Pet Poison Helpline at 855-764-7661. Consultation fees may apply.

When to Be Concerned About Your Cat’s Vomiting

Occasional vomiting in cats isn’t always a cause for alarm, but knowing when to worry can make all the difference. If your cat’s vomiting becomes frequent, severe, or is accompanied by other symptoms like lethargy, weight loss, or changes in appetite, it could signal a deeper health issue. 

This section will guide you through understanding when your cat’s vomiting is more than just a minor upset and what steps you should take next.

grey and white cat vomiting food because it ate too quickly

Frequency and Duration of Vomiting

It’s normal for cats to vomit occasionally, as they often do so to expel indigestible matter like hairballs. However, if your cat vomits multiple times in a day or consistently over several days, it’s a sign that something may be wrong. 

Persistent or chronic vomiting, especially if accompanied by symptoms like lethargy, diarrhea, or a decrease in appetite, warrants a visit to the veterinarian. These signs could indicate a serious health issue that needs immediate attention.

Content and Consistency

Here’s a list of what to look for in your cat’s vomit and what these signs might indicate:

  • Normal:
    • Clear Liquid: Often just stomach bile, indicating an empty stomach.
    • Foamy Liquid: Typically not a concern unless it’s frequent.
    • Hairballs: Common in cats, especially those with longer fur.
  • Potential Concerns:
    • Undigested Food: Could suggest rapid eating or digestive issues.
    • Brothy, Watery Foam: May indicate gastritis or irritation of the stomach.
    • Dark or Coffee Ground-like Material: Indicates digested blood; could be a sign of serious conditions like ulcers or internal bleeding.
    • Chunks of Food with Blood: Suggests gastrointestinal bleeding or blockages.
    • Green or Yellow Bile: Signifies bile reflux, which might occur if the cat is vomiting on an empty stomach repeatedly.
    • Large volumes of watery vomit: If the intestine is blocked, then nothing can pass through. Anything that is in the cat’s stomach cannot exit the normal way, and the stomach can only empty via vomiting.

Accompanying Symptoms

If vomiting is accompanied by other symptoms such abdominal pain, weight loss, or changes in appetite, take your cat to the vet immediately. There is likely something very serious going on that needs medical intervention.

Changes in Appetite and Weight

Monitor your cat’s normal eating habits and weight. Occasional vomiting of undigested food can indicate your cat is simply eating too quickly. But significant weight loss accompanying frequent vomiting episodes is concerning and warrants a trip to the veterinarian.

Diagnosing the Cause of Your Cat’s Vomiting

Diagnosing the cause of frequent vomiting in cats begins with a thorough history from the owner and a physical examination of the cat by a veterinarian. This helps rule out obvious causes and guides the diagnostic process.

Laboratory Tests

Bloodwork and fecal examination are often the next steps to rule out possible toxicities, parasites, and metabolic diseases as the cause of a cat’s persistent vomiting. These lab tests provide important information that will help the vet figure out what the underlying problem might be.

Imaging Studies

If lab work is normal, x-rays and ultrasound may be recommended. These imaging studies can be helpful in finding masses, foreign objects, and other gastrointestinal tract problems that could be causing a cat’s vomiting.


In some cases, an endoscopic procedure may be pursued to visualize the inside of a cat’s stomach and intestines. This minimally invasive diagnostic tool allows veterinarians to look for signs of inflammation, ulcers, foreign bodies or masses.

Exploratory Surgery

If other diagnostic tests are not fruitful in determining the cause of chronic vomiting, an exploratory surgery may be necessary. This allows direct visualization of the cat’s internal organs to look for abnormalities and possibly biopsy the intestinal tract to rule out cancer or inflammatory bowel disease.

grey cat outdoors throwing up undigested food

Home Remedies and Supportive Care for Vomiting Cats

If your cat’s been throwing up, you’re probably feeling pretty helpless. Most cat owners have been there at one time or another. It’s tough watching your pet suffer and not knowing how to make it better.

The good news? There are some simple things that you can do at home that can provide much-needed relief for your vomiting cat.

Withholding Food and Water

One of the first things you should do if your cat is vomiting is withhold food and water for a few hours. I know it sounds harsh, but giving their digestive system a break can help settle their stomach. After 6-8 hours, slowly reintroduce small amounts of water. If they keep that down, offer a bland diet in small quantities. More on that next.

Bland Diet

A bland diet is so important for easing your cat back into eating after vomiting episodes. Think simple, easily-digestible ingredients like boiled chicken breast, white fish, or even meat-flavored baby food (just check that it doesn’t contain onion or garlic powder). 

You can also try specially-formulated cat foods for digestive issues, like Royal Canin® Feline Gastrointestinal or Hill’s ID®. These provide the nutrition your cat needs while being gentle on the stomach. Just remember, no people food long-term. It doesn’t provide the complete nutrition cats need. Stick to a vet-recommended diet to keep your kitty healthy.


Probiotics can be a lifesaver for cats with frequent digestive issues and vomiting. They help restore the natural balance of good bacteria in your cat’s gut. 

I’ve had great success using FortiFlora® probiotic supplements with my own cats. It comes in a palatable powder you can mix right into their food. Easy peasy. Always check with your vet first though. They can recommend the best probiotic for your cat’s specific needs.

Hairball Remedies

Hairballs are often the culprit behind cat vomiting. When cats groom themselves, they  swallow loose fur that can accumulate in the digestive tract. If it doesn’t pass through the stool, up it comes. Brushing your cat regularly is the best defense against hairballs. The more fur you remove, the less they ingest. 

There are also over-the-counter hairball remedies that contain lubricating gels that help hair pass through the digestive system more easily. Treatments containing papaya extract, which contains an enzyme that breaks down the mucous that holds hair balls together, can also be helpful. I’ve used this successfully in cats where the lubricating hairball remover just doesn’t work. 

Preventing Access to Toxic Plants

Cats are curious creatures and love to nibble on plants. Unfortunately, many common houseplants are toxic to cats and can cause vomiting if ingested. Some of the biggest offenders include lilies, sago palms, tulips, and azaleas.

If you’re not sure if a plant is safe, err on the side of caution and keep it out of kitty’s reach. You can also opt for cat-safe plants like catnip, cat grass, and spider plants. These provide safe, enriching nibbling opportunities for your feline friend.

sad looking scottish fold cat

Preventing Future Episodes of Vomiting in Cats

An ounce of prevention is worth a pound of cure, right? When it comes to cat vomiting, there are several steps you can take to keep those episodes at bay.

Regular Deworming

Intestinal parasites are a common cause of vomiting in cats, especially kittens and outdoor cats. The best defense? Regular deworming. Most monthly flea/tick preventatives also protect against common intestinal parasites. I use Revolution Plus® for my crew. It’s a simple topical treatment that keeps them pest-free and parasite-free. 

Depending on your cat’s lifestyle, your vet may recommend deworming more or less frequently. Indoor cats are lower risk, while outdoor adventurers need more frequent treatment.

Hairball Management

We already talked about hairball remedies, but management is an ongoing process. Brushing is your BFF when it comes to preventing hairballs and the vomiting they cause. Make grooming a regular part of your routine, especially for long-haired breeds. Aim for a thorough brushing at least once a week, along with regular preventative hairball treatment.

You can also try a hairball control cat food. These high-fiber formulas are designed to minimize hairball formation and keep things moving through the digestive tract.

Gradual Diet Changes

Cats are creatures of habit and their digestive systems can be sensitive to sudden changes. Abruptly switching foods can lead to vomiting and diarrhea. 

If you need to change your cat’s diet for any reason, do it gradually over 7-10 days. Mix increasing amounts of the new food with decreasing amounts of the old food until you’ve made a complete switch. This gives their gut time to adjust to the new ingredients and can prevent digestive upset. Slow and steady wins the race.

Avoiding Toxic Substances

Cats are curious and love to investigate their environment, but many common household items can be toxic if ingested. Some key things to keep out of paw’s reach include:

  • Medications (both human and pet)
  • Cleaning products
  • Insecticides and rodenticides
  • Antifreeze
  • Certain foods like onions, garlic, chocolate, and xylitol

Most of the items are a medical emergency if your cat gets into them. Keep these items securely stored and clean up any spills immediately. A little cat-proofing goes a long way in preventing accidental poisoning and the vomiting it can cause.

Stress Reduction Techniques

Believe it or not, stress can cause vomiting in cats. Cats are sensitive creatures and changes in routine, new pets, or even rearranged furniture can cause anxiety. 

If your cat is prone to stress vomiting, try using calming aids like Feliway® pheromone diffusers. These emit a synthetic version of the feline facial pheromone, which has a natural calming effect.

Maintaining a consistent routine, providing plenty of enrichment (think puzzle feeders, scratching posts, and interactive playtime), and using positive reinforcement training can also help reduce stress and keep vomiting at bay.

Key Takeaway: Watching your cat throw up is tough, but you’re not powerless. From giving their tummy a break with no food or water for a few hours to easing them back into eating with a bland diet and probiotics, there are steps you can take. Regularly brushing your cat and using hairball remedies helps too. Don’t forget to keep toxic plants and substances out of reach, manage stress, deworm regularly, and introduce dietary changes slowly. These simple tips can make a big difference in preventing future vomiting episodes.


Dealing with a cat that keeps throwing up can be stressful and worrisome. But by understanding the common causes and taking proactive steps, you can help your feline friend feel better.

Frequent vomiting or other signs of illness in your cat? Don’t ignore them – your vet is your ally in figuring out what’s wrong and creating a targeted treatment plan. Trust their expertise to guide your feline friend back to wellness.

With a little patience, care, and the right approach, you can help your cat overcome their vomiting issues and get back to living their best nine lives.

[Image credits: All images are used under license or with permission]


  • Dr. Wendy Wilkins DVM PhD.

    Dr. Wendy Wilkins is an experienced veterinarian and epidemiologist with over 20 years of expertise. She holds a Doctor of Veterinary Medicine (DVM) degree and a Doctorate in Epidemiology from the University of Saskatchewan. Throughout her career, Dr. Wilkins has excelled in clinical practice, academia, research, and regulatory veterinary medicine. She is a respected voice in knowledge dissemination, delivering factual information in a readable and understandable manner through articles, books, and public engagements.

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