Cat Vomiting and Diarrhea: Top Causes and Treatments

Nothing feels quite as helpless as knowing your treasured cat isn’t feeling well. Sure, every cat pukes up a hairball every now and then. But when your cat is really vomiting or having diarrhea, you know something else is wrong. What do you do next? Is your cat sick? Do you need to go to the veterinarian? This guide will help you understand what can cause cat vomiting and diarrhea and how you can help your precious friend feel better.

Sometimes you’ll get a clear clue right away, such as yellow bile from an empty stomach,1 blood-tinged diarrhea pointing to lower intestinal inflammation and bleeding2 or barely digested food possibly pointing to eating too fast.But often, you’ll have to watch for other symptoms or surrounding circumstances for clues about when to worry.

Cat vomiting and cat diarrhea causes can vary widely, including dietary, gastrointestinal, medical and environmental. Here’s a closer look at each.

Dietary causes of cat diarrhea and vomiting

The first thing to consider is that your cat’s food might be the culprit.

1. Spoiled or contaminated food

Spoiled or contaminated food can cause cat diarrhea and vomiting.1 Check to see if the food is expired or recalled.Kibble usually has a good shelf life, but if you’re feeding a freeze-dried or fresh diet, or if you rely on canned food and accidentally leave it out too long, the food has potential to harbor harmful bacteria.

2. Eating too quickly, too much or not enough

If your cat quickly throws up what seems to be undigested food right after eating and then seems fine, she might be vomiting because she overate or ate too fast.Cats that eat meals rather than grazing all day may be more prone to this. Cats with a high food drive are also more likely to overeat or eat too quickly.

Switching to canned food can help prevent the expansion of kibble in the stomach, triggering vomiting. Consider using an automatic feeder that dispenses a small amount of food throughout the day to prevent overeating in one sitting.

Going too long without food can cause the same reaction. The acid in your cat’s stomach might have built up, leaving him nauseous.5 He may need more frequent, small meals to prevent this.

3. Non-food items, poisons or toxic food

When it comes to what they eat, cats tend to be a little more discretionary compared to dogs. But some cats are intrigued by string, hair ties, dental floss and other nonfood items. If something that isn’t food gets caught in your cat’s throat,4 stomach or even in the intestines,1 the obstruction can cause vomiting.

Some poisons or toxic foods can also cause vomiting1 or diarrhea.This could include some plants containing oxalates, like Pothos or Peace Lily, which are irritating to the gastrointestinal tract. This can affect both indoor cats and outdoor cats.

Did your cat get into chocolate? Your medicine? Pesticides? Signs of poisoning may include difficulty breathing, drooling, collapsing or shaking.3 Call your veterinarian or animal poison control immediately.

4. Food allergies

Food allergies can cause diarrhea or vomiting.2 If you give your kitty a new type of treat, for example, you might stumble upon an allergy. Additionally, cats can develop food allergies at any time. Food that once was fine may start to be an issue. The ingredient that typically causes an allergy is the protein source, so switching to a different protein (e.g., swapping fish or chicken for beef or turkey) may help.

5. Changes in food

Sudden changes in food can cause your cat to vomit1 or develop diarrhea.Cats’ stomachs can be sensitive and need time to adjust. Start by mixing a little new food in with the old food, gradually increasing the new and decreasing the old.

Gastrointestinal causes of cat vomiting and diarrhea

If you’re wondering, “Why is my cat having diarrhea or vomiting?” the issue might be with the gastrointestinal system itself.

1. Inflammatory bowel disease

Inflammatory bowel disease can cause chronic vomiting or diarrhea.6 Other symptoms may include gas, blood in the stool, weight loss, change in appetite or accidents outside the litter box.

2. Infections and viruses

Infections from protozoa or bacteria can cause diarrhea.2 Vomiting and sneezing at the same time might indicate a virus or an upper respiratory tract infection.Your veterinarian can test for these.

3. Intestinal parasites

Intestinal parasites can also cause symptoms that include diarrhea (sometimes bloody) or vomiting in cats, with young animals being at risk of life-threatening disease.7 Examples include roundworms, hookworms, whipworms and coccidia. Weight loss and poor hair coat are often other symptoms.

Medical causes of cat vomiting and diarrhea

Sometimes vomiting or diarrhea might be caused by a medical issue that isn’t actually related to the stomach or intestines.

1. Kidney disease

Kidney disease has the potential to be a serious illness.8 Typically, this affects older cats more than younger cats. Symptoms include increased thirst and urination. Sometimes, larger clumps of urine in the litter box are one of the only signs. Some cats will start to refuse food and lose weight. Vomiting and diarrhea can accompany kidney disease in its later stages.

2. Pancreatitis

Pancreatitis can also cause serious illness.9 Pancreatitis can be challenging to diagnose, as cats can have a variety of symptoms ranging from just hiding and acting like they’re in pain to losing weight and exhibiting decreased appetite or activity. Some cats may vomit and have loose stools, sometimes missing the litter box. Pancreatitis has the potential to be painful and life-threatening. If you suspect this illness in your cat, seek veterinary help.

3. Liver disease

Liver disease can occasionally present with vomiting1 or diarrhea.2 Liver illnesses can be caused by a variety of things, some of which are serious. In addition to vomiting and diarrhea, you may see inappetence, behavior changes such as hiding, and color in the whites of the eyes or skin. If you suspect a liver issue as a cause for vomiting and diarrhea in your cat, veterinary care is imperative.

4. Cancer

Cancer is a devastating diagnosis, and depending on where the cancer is located, it may result in vomiting and diarrhea. This is especially seen with cancers of the stomach and small intestine.

5. Diabetes

Diabetes is a disorder of the pancreas, which loses its ability to produce insulin. The most common sign of diabetes is increased thirst and rapid weight loss. But as the diabetic cat switches from burning glucose to using ketones, dangerous toxins can build up, causing diarrheaor vomiting.1 In addition, if your cat gets so thirsty that he drinks too much water, he may even throw that up.4

6. Asthma

If your cat seems to retch but doesn’t actually vomit, she might really be coughing.1 Sometimes it can be difficult to tell these apart! One possible culprit of coughing that looks like retching is asthma, which can be triggered by dust mites, allergens like pollen or mold and even some foods.10

Environmental causes of cat vomiting and diarrhea

1. Stress or anxiety

Cats can sometimes vomit or have diarrhea simply from stress.11 All sorts of things can cause stress, like changes in routine, traveling in a car or even another animal. Signs of stress might include hiding, overgrooming, having accidents outside the litter box or becoming irritable or more vocal.10 These can also be signs of illness, so see your veterinarian.

2. Hairballs

Typically when cats groom themselves, they ingest some hair.12 Occasionally it gets vomited as a hairball. You can’t stop your cat from grooming himself,9 but regular brushing can get rid of most loose fur before he swallows it. Hairballs are considered normal, so vomit with fur in it is generally not a reason to call the vet. Your veterinarian, however, might recommend a remedy to help pass the hairball more easily.

When to see a veterinarian

If vomiting or diarrhea lasts for more than 24 hours, if your cat vomits three times in a row or has other symptoms like lethargy, blood in the vomit or stool, appetite loss or cessation of drinking, see a veterinarian ASAP. If your cat vomits more than once a week or off and on for several months, you’ll also want to see a veterinarian.1 When it comes to these issues, it’s best to err on the side of caution.

How a veterinarian will diagnose and treat your cat

Your veterinarian will likely start out with noninvasive tests, including a physical exam, general bloodwork, abdominal ultrasounds or X-rays.4 They may run fecal tests to look for infections or parasites.Your veterinarian may recommend a prescription gastrointestinal diet or medication to help reduce vomiting and firm up the stool.

After this first wave of diagnostic testing, the next step might be general anesthesia for an endoscopy, which involves putting a flexible tube with a video camera into the esophagus and stomach.4 Your cat might also be given a contrast dye for a swallow study.

Depending on the cause, the treatment could range from surgery to extensive medication. Your veterinarian might even recommend a home remedy for cat vomiting and diarrhea, like extra fiber or canned pumpkin.2

Preventing vomiting and diarrhea

While there are many illnesses that can’t always be prevented, you can do a lot to help your cat avoid nausea, diarrhea or vomiting in the future:

  • Feed your cat a healthy diet2
  • Introduce new food gradually2
  • Use allergen-friendly or fiber-rich food, if veterinarian-recommended4
  • Reduce stressful triggers11
  • Feed smaller, more frequent meals5
  • Use slow-feeder bowls or automated feeders4

From Pets Best

Of course, the best way to keep your cat healthy is by getting regular checkups with your veterinarian. Pets Best cat insurance plans with optional routine care coverage can help you afford those regular appointments and be ready when unexpected vomiting or diarrhea happens. Pets Best policyholders can also call a veterinary expert anytime through a 24/7 Pet Helpline. This offers an easy way to find out what to feed a cat with diarrhea or vomiting, even if the problem crops up after the veterinarian’s office hours.


1Meeks, Cathy. (2021, January 28). Why Your Cat is Throwing Up and What To Do. PetMD.

2Newett, Heather. (2021, January 28). What Causes Cat Diarrhea and What to Do About It. PetMD.

3(2022, November 24). Diarrhoea and Vomiting in Cats. Blue Cross.

4Grzyb, Katie. (2022, September 23). Cat Regurgitation. PetMD.

5(2021, November 22). Possible Causes for Your Cat Vomiting Clear Liquid. River Landings Animal Clinic.

6(2022, May 23). Cat Vomiting, Diarrhea, Bloody Stool – Irritable Bowel Disease in Cats. River Landings Animal Clinic.

7Intestinal Parasites in Dogs and Cats. Pet Medical Center.

8Kearley, Michael. (2022, May 9). Kidney Disease in Cats. PetMD.

9Kearley, Michael. (2022, March 2). Pancreatitis in Cats. PetMD.

10(2022, July 30). Cat Asthma: Symptoms and Treatments. Fremont Veterinary Clinic.

11Hitchcock, Kristin. (2023, January 17). Do Cats Vomit When Stressed? Deciphering Your Cat’s Behavior. Pet Keen.

12(2019, March 25). Hairballs in Cats (Feline Trichobezoars.) PetMD.

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