Seeing a cat with simultaneous vomiting and diarrhea can be scary for a pet owner. Why is this happening? Is it serious?

Just about every cat suffers from an upset tummy once in a while. But if vomiting and diarrhea are happening at the same time, you need to get your pet medical attention. Both can lead to potentially dangerous dehydration. There could also be an overgrowth of bacteria in the stomach.

These are just some of the potential reasons why cat vomiting and diarrhea may occur at the same time.

Food Allergies

Food allergies are common among cats. While the most common symptoms of this illness include itchy skin, acute vomiting and chronic diarrhea may also happen. This is because a food allergy can lead to problems affecting the gastrointestinal tract, or GI tract.

Digestive upsets due to food intolerance or intolerance to cow’s milk can also result in a loss of appetite. This, in turn, can result in a potentially dangerous amount of weight loss.1

Talk to your vet if you suspect your cat has a food allergy to something in his or her diet. They may suggest trying something different at feeding time, such as a different brand of cat food.

Feline Gastroenteritis

If a cat is experiencing vomiting or diarrhea, or has both at the same time, one potential cause is feline gastroenteritis. This illness occurs when the gastrointestinal tract becomes inflamed. Several things could lead to feline gastroenteritis, including:

  • Feeding a new food, or changing the cat’s diet in some other way
  • Eating spoiled food
  • Certain medications
  • Foreign bodies in the stomach (such as string)
  • Bacterial infection

vomiting and diarrhea | Dr Marty PetsSymptoms of this illness not only include chronic diarrhea and frequent vomiting, but also pain in the abdomen.

In many cases, a cat will show discomfort when picked up near the stomach area. Lethargy and hiding are other signs. Cats will often have loose bowel movements several times a day.2

Have your cat checked for excessive bacteria if they’re experiencing chronic vomiting or any symptoms. If your cat is vomiting blood or has blood in their stools, get to the vet as quickly as possible.

Feline Infectious Peritonitis

Feline infectious peritonitis, or FIP, is caused by a virus known as feline coronavirus. In many instances, a cat with the virus won’t show any symptoms when first infected. The immune system produces antibodies to kill the virus. About 5-10 percent of the time, however, a cat will develop feline infectious peritonitis.

When this happens, the virus can travel to organs throughout the body, including the stomach and brain. FIP is a very serious condition. Symptoms include loose bowel movements, chronic vomiting, nasal discharge, fever and others.3

Hepatic Lipidosis

Hepatic lipidosis is a disease which affects the liver and intestinal region. It occurs when a cat’s body produces more fat than the liver can redistribute.

Stress may contribute to this liver disease. For example, a cat might resist you feeding them a new brand of food, and will suffer severe weight loss as a result.

The loss of a family member or pet, or the introduction of a new pet or human to the household, can also cause serious stress.

Symptoms of hepatic lipidosis include frequent vomiting and chronic diarrhoea, lethargy, and a lack of bowel movements. There could also be other issues involving the gastrointestinal tract.4

By the way, changes to a cat’s environment have been linked to other problems that have nothing to do with vomiting. For example, a cat may be more susceptible to a urinary tract infection after some sort of change occurs.5

Pancreatic Insufficiency

The pancreas has two main jobs. One is to produce digestive enzymes to break down food. The other is to produce insulin, a hormone that regulates the amount of sugar (glucose) in the blood. Pancreatic insufficiency occurs when the pancreas can’t produce enough digestive enzymes.6

Pancreatic insufficiency in cats can lead to intestinal problems. These include digestive upsets and an overgrowth of intestinal bacteria. Symptoms include weight loss, chronic vomiting, chronic loose stools, and others.7

vomiting and diarrhea | Dr Marty Pets

Feline Leukemia Virus

Feline leukemia virus (FeLV) is a serious disease that weakens the immune system, making a cat vulnerable to even more severe health issues. Feline leukemia virus is often fatal. But the good news is, the FeLV vaccine may significantly lower the risk of developing the disease.

Symptoms of FeLV include acute diarrhea (which can lead to dehydration) and acute vomiting. Other symptoms include gradual weight loss, lethargy, and fever. Otherwise, healthy cats can contract the virus and not show symptoms for years.8

Talk to Your Veterinarian

As you can see, vomiting and diarrhea at the same time can be a serious problem. It can be a sign of a potentially dangerous condition, and it can also lead to dehydration. If your cat is experiencing diarrhea and vomiting, get them to the vet as soon as you can.

In many instances, medications may be able to solve the problem. But if medications don’t work, your vet will determine other alternatives to address the issue. Your vet may recommend changing your pet’s diet or changing another part of his or her health care routine.

Learn More:
Understanding Cat Sounds – What’s Your Cat Telling You?
Cat Eye Infection – Causes, Symptoms, & Prevention
Obligate Carnivores: Why Meat is Essential to Your Cat’s Well-Being


DisclosureThe Dr Marty’s Pets team creates these articles as a way to provide you with the latest information on health and nutrition. Unfortunately, we cannot make specific product recommendations for our website visitors, such as “Dr Marty’s Nature’s Feast” or “Feline Prime” Please consult with your healthcare provider to determine the best products for you.