Skip to main content

Cat throwing up white foam: A vet's guide to causes and treatment

Cat throwing up white foam
(Image credit: Getty Images)

Watching your cat throwing up white foam is sure to incite panic in most cat owners. While the occasional hairball is something that many of us have become accustomed to seeing, unexpected puddles of white, frothy vomit can be an entirely different story. 

There are many reasons that cats can vomit, ranging from mild to severe. Perhaps your cat ate a treat to which they aren’t accustomed and it upset their stomach, or there could be a significant internal disease process at play. Before you panic or (even worse) decide to ignore your cat’s vomiting, read on to learn more about how you and your veterinarian can work together to address vomiting in cats. 

Why is my cat throwing up white foam? 

White, foamy vomit usually means that your cat vomited when they had an empty stomach. Your cat’s stomach typically contains a small amount of fluid and mucous between meals, and this is likely what you are seeing in their vomit. So, on the plus side, the presence of white foam in and of itself is not especially concerning. However, it’s still important to get to the bottom of why your cat is vomiting in the first place!

There are many potential causes of vomiting in cats. Isolated episodes of vomiting may not have a clearly identifiable reason, while consistent or recurrent vomiting is more likely to reflect an underlying disease process. 

Potential causes of vomiting in cats include:

  •  Dietary indiscretion (eating a new treat or food) 
  •  Intestinal parasites 
  •  Inflammatory bowel disease 
  •  Food allergy 
  •  Gastrointestinal infection (bacterial or viral) 
  •  Intestinal cancer 
  •  Foreign body obstruction 
  •  Hairball obstruction 
  •  Medication reaction 
  •  Pancreatitis 
  • Heartworms 
  • Hyperthyroidism 
  • Renal failure 
  • Liver disease 

cat lying on floor

(Image credit: Getty Images)

When should you be concerned about your cat throwing up with white foam

A single episode of vomiting doesn’t necessarily require veterinary care, as long as your cat is acting otherwise normal. If your cat vomits once, but then immediately returns to playing and eating normally, you can probably hold off on calling your veterinarian. Monitor your cat closely and ensure that there are no further episodes of vomiting or other signs of illness. 

However, if your cat’s vomiting persists for longer than 24 hours or you notice other signs of illness, such as diarrhea, lethargy, or refusal to eat, you should have your cat evaluated by a veterinarian. 

There are many potential causes of vomiting in cats. Trying to figure out the cause of your cat’s vomiting by yourself, or with the help of the Internet, is likely to be an exercise in futility. A physical examination and laboratory tests will likely be needed to determine the cause of your cat’s vomiting.

Repeated vomiting can lead to dehydration. Additionally, vomiting cats can develop hepatic lipidosis (fatty liver disease) if they are unable to keep down adequate amounts of food. Your veterinarian can assess your cat’s hydration, determine whether fluid therapy is needed, and address your cat’s vomiting to prevent further fluid loss and reduce the risk of hepatic lipidosis.

Diagnosing the cause of vomiting in cats

Your veterinarian will begin by performing a thorough physical examination of your cat. They will listen to your cat’s heart and lungs, palpate your cat’s abdomen for any internal abnormalities, and observe your cat’s overall body condition. 

Based on these physical exam findings, your veterinarian will then recommend appropriate diagnostic tests for your cat. Initial testing may include blood tests (such as a complete blood cell count or CBC, serum biochemistry profile, and thyroid level), fecal parasite testing, urinalysis, and/or abdominal radiographs (x-rays). If these screening tests do not provide a diagnosis, your veterinarian may recommend more targeted testing, such as an abdominal ultrasound, a food allergy trial, or surgical biopsies of your cat’s intestines. 

In some cases, multiple tests may be necessary to arrive at a diagnosis and determine the best treatment plan for your cat. Your veterinarian may refer your cat to a veterinary specialist for portions of this diagnostic workup, depending on what testing your cat needs. 

cat visiting the vet

(Image credit: Getty Images)

Can I treat my cat’s vomiting at home?  

There are no at-home treatments that you can safely give your cat to prevent or treat vomiting. Human medications can be toxic to cats, causing problems that are even worse than the vomiting that you are trying to treat. Resist the temptation to use home remedies and follow your veterinarian’s guidance.

Treating vomiting in cats 

If your cat has had an isolated episode of vomiting with no apparent underlying disease, your veterinarian may administer an injection of an anti-nausea drug to settle your cat’s stomach. You may also be sent home with oral anti-nausea medications to give your cat, as well as a short course of a bland, prescription diet for gastrointestinal health. In some cases, symptomatic care is all that is needed to get a cat over an upset stomach.

In more severe cases, involving ongoing or severe vomiting, your cat may require hospitalization. This will allow your veterinarian to administer intravenous fluids and injectable medications, while closely monitoring your cat. Hospitalization can be used to rehydrate your cat and get vomiting under control, allowing your cat to come home with you for ongoing outpatient care.  

Ultimately, the treatment of vomiting depends on the underlying cause. If your cat has a food allergy, a simple diet change may be enough to prevent future vomiting episodes. Intestinal foreign bodies (if your cat ate a piece of string or toy that is lodged in the intestines) may require surgical removal. Once your veterinarian has diagnosed the cause of your cat’s vomiting, they will recommend the best treatment options for your cat. 

Work with your veterinarian 

If you witness your cat throwing up white foam, it’s important to note whether this is an isolated or recurrent issue. A single episode of vomiting can occur for any number of reasons and may not always require veterinary care. 

However, repeated episodes of vomiting or vomiting that is accompanied by other signs of illness calls for a veterinary visit. Work with your veterinarian to determine the cause of your cat’s vomiting, and how you can treat your cat’s vomiting effectively and safely.  

Catherine Barnette DVM

Dr. Barnette received both her Bachelor of Science degree in zoology and her Doctor of Veterinary Medicine from the University of Florida. She’s an experienced writer, educator, and veterinarian, with a passion for making scientific and medical information accessible to public and professional audiences.