Why Is My Cat Throwing Up White Foam? The Reasons Behind This Concerning Symptom


Seeing your cat throw up white foam can be alarming for any pet owner. Vomiting is a common symptom for many health issues in cats, so it’s normal to be concerned when it happens. Throwing up white foam or fluid, rather than food contents, can indicate there’s a problem somewhere in your cat’s digestive tract.

White foam vomit often occurs when a cat’s stomach and esophagus are irritated by something, causing muscle contractions to bring up fluid and saliva. It may also result from an empty stomach when bile mixes with their gastric juices. While an occasional episode of white foam vomit may not be serious in an otherwise healthy cat, recurring instances definitely warrant a trip to the vet to identify the underlying cause.

This article will examine the possible reasons why a cat may throw up white foam, from harmless hairballs to more serious conditions like poisoning. We’ll also provide tips on how to care for a vomiting cat, when to seek veterinary help, and how to reduce episodes in the future.

Possible Causes

There are several possible causes for a cat throwing up white foam:


Cats groom themselves by licking their fur, which causes them to ingest hair. If too much hair builds up in the stomach and intestines, it can form a hairball that leads to vomiting. As the vomit comes up, stomach acids turn it into white foam. Hairballs are a very common reason for cats throwing up white foam. Preventing hairballs involves regular brushing and grooming, as well as feeding hairball remedy treats or food [1].

Acid Reflux

Acid reflux occurs when stomach acid flows back up into the esophagus. This irritation can cause vomiting of white foam. Acid reflux may happen if your cat eats too quickly or eats a very large meal. Feed smaller, more frequent meals and have your vet examine your cat if acid reflux vomitting persists [2].

Empty Stomach

Throwing up bile and foam is common in cats with empty stomachs. Their bodies produce excess stomach acid without any food to digest, which leads to irritation and vomiting. Make sure your cat isn’t going too long between meals by feeding smaller amounts more often [3].


Ingesting toxins like household cleaners, plants, or human medications can cause a cat to vomit white foam. Take note of any potential toxins your cat could have accessed. Call your vet or the ASPCA poison control line if you suspect poisoning.


Hairballs are a common cause of cats vomiting white foam. As cats groom themselves, they ingest hair. If too much hair accumulates in the stomach, it can form a hairball that is vomited up. Hairballs are not usually dangerous, but can cause vomiting and discomfort.

Symptoms of hairballs include vomiting white foamy liquid, gagging or coughing, lack of appetite, and lethargy. If the hairball passes through to the intestines, symptoms may also include constipation and straining to defecate.

Treatment for hairballs involves using a cat laxative like Laxatone to help lubricate the hairball and allow it to pass through the digestive tract more easily. Adding more fiber to the diet can also help. Preventatively, grooming and brushing your cat regularly can reduce the amount of loose hair ingested (Source). In some cases, surgery may be required to remove a large hairball that is obstructing the intestines.

Acid Reflux

Acid reflux, also known as gastroesophageal reflux disease (GERD), occurs when stomach acid frequently flows back up into the esophagus. This can irritate the lining of the esophagus and cause symptoms like vomiting white foam.

When a cat has acid reflux, stomach acid backs up into the esophagus. The esophagus is not equipped to handle this acidity, so it becomes inflamed and irritated, which can trigger vomiting. Vomiting brought on by acid reflux often consists of white foam or liquid, since little food is present in the stomach.

Treatment for acid reflux in cats focuses on reducing stomach acid production and protecting the esophagus. Vets may prescribe medications like proton pump inhibitors or H2 blockers, as well as recommend feeding several small meals throughout the day rather than one large meal. Lifestyle and diet changes can also help minimize episodes of reflux and vomiting.

Empty Stomach

An empty stomach is one of the most common causes of a cat vomiting white foam. When a cat’s stomach is empty, bile comes up from the digestive tract. This bile mixes with air to create the foamy appearance. As Cats.com explains, “A cat will vomit foam when the stomach and upper intestines are empty.” Cats.com

When a cat goes too long without eating, the stomach secretes digestive acids and moves bile into the stomach in preparation for food. Without food to process, these fluids can irritate the stomach lining, leading to nausea and vomiting. The white foam occurs because there is no solid food content to regurgitate.

To prevent vomiting on an empty stomach, it’s important to feed cats small, frequent meals rather than one large daily meal. This helps ensure the digestive system has food to process. It’s also a good idea to monitor appetite and eating habits. Any changes could be an early sign your cat needs to see the vet.


One potential cause for a cat vomiting white foam is poisoning from ingesting toxic substances. Common household poisons that could lead to this symptom include antifreeze, rat poison, household cleaners, human medications, and toxic plants.

Symptoms of poisoning besides vomiting white foam can include lethargy, dilated pupils, difficulty breathing, tremors or seizures, and collapse. It is crucial to get emergency veterinary care right away if poisoning is suspected.

Some steps to take immediately if you believe your cat may have ingested something toxic include:

  • Remove your cat from the area and source of the toxin if possible.
  • Call your veterinarian, emergency vet clinic, or poison control hotline.
  • Follow their recommendations, which may include inducing vomiting or rushing your cat to the vet clinic.
  • Bring a sample of the potential toxin with you to the vet if available.

Quick action is essential when poisoning may have occurred, as many toxins can cause severe, irreversible organ damage or even death if not treated promptly. Do not wait for other symptoms to develop. Get emergency veterinary help right away if poisoning is possible.

Other Causes

Some other potential causes for a cat throwing up white foam include:

Liver disease: Liver disease, such as hepatitis or hepatic lipidosis, can lead to gastrointestinal issues and vomiting. The liver helps digest food, so liver problems can result in indigestion and bile building up in the stomach. [1]

Parasites: Intestinal parasites like roundworms, hookworms, or giardia can irritate the digestive tract lining and cause nausea and vomiting. Parasites compete for nutrients, impair proper digestion, and damage the intestinal walls. [2]

Cancer: Feline lymphoma, intestinal cancer, or other cancers affecting the digestive system may lead to vomiting white foam. Cancer can cause obstruction, inflammation, or bleeding in the gastrointestinal tract. [3]

Kidney disease: Kidney disease can cause nausea and vomiting, as improper filtration of blood causes a buildup of toxins. The kidneys help regulate hydration and electrolyte levels, so renal problems disrupt fluid balances. [2]

Ingesting toxins: If a cat ingests toxins like household cleaners, plants, or human medications, it can irritate the digestive tract and cause vomiting. Chemical toxins directly damage the stomach and intestinal lining. [3]

When to See the Vet

In most cases, an occasional episode of vomiting white foam is not an emergency. However, there are some red flags and symptoms that warrant a veterinary visit:

  • Repeated vomiting episodes – If your cat vomits white foam multiple times within a few hours or over the course of a day or two, it likely indicates an underlying health issue that needs attention.
  • Lethargy – If your cat seems overly tired, weak, or generally unwell along with the vomiting, it could signal something more serious like poisoning or pancreatitis. Seek vet care.
  • Diarrhea – Vomiting paired with diarrhea is cause for concern, as it suggests possible infection or inflammation in the GI tract.
  • Loss of appetite – If your cat refuses food after throwing up white foam, it is not getting proper nutrition and at risk for complications like hepatic lipidosis.
  • Dehydration – Look for tacky gums, sunken eyes, weakness, and excessive lethargy as signs your cat may be dehydrated from fluid loss due to vomiting.
  • Difficulty breathing – Labored breathing, wheezing, or panting accompanying the vomiting points to a potentially life-threatening issue needing emergency vet treatment.
  • Blood in the vomit – Any sign of blood (red specks or bigger amounts) indicates internal injury or bleeding that requires prompt veterinary attention.

If your cat exhibits any of the above symptoms along with vomiting white foam, call your vet right away or go to an emergency animal hospital. Timely treatment greatly improves the chances of a full recovery.


There are a few things cat owners can do to help prevent episodes of vomiting white foam:

Control hairballs – Long haired cats are prone to hairballs that can cause vomiting. Brushing cats regularly helps remove loose hair they ingest while grooming. Feeding a hairball control cat food or treat can also help cats pass hairballs more easily before they cause irritation and vomiting.

Feed on a schedule – Feeding cats 2-3 scheduled meals per day rather than free feeding can help prevent vomiting from an empty stomach. Spread meals throughout the day so the stomach isn’t empty for long periods.


Cats vomiting white foam can be concerning for pet owners, but it is often caused by benign conditions like hairballs or eating too quickly. The foam itself comes from irritated stomach acids or ingested substances like detergent or plants. Some key takeaways include:

  • Look for other symptoms like lethargy or diarrhea to gauge severity.
  • Remove access to toxins and feed cats more slowly to prevent vomiting.
  • Try home remedies like lubricating hairball gel and peppermint treats.
  • See the veterinarian right away if vomiting persists more than 24 hours or is accompanied by other concerning symptoms.

While vomiting foam is common in cats, persistent or severe cases should always be evaluated by a vet as they can indicate serious medical issues. With attentive care and occasional vomiting, most cats fully recover and feel better after getting treatment for the underlying cause.

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