Why Is My Cat Throwing Up White Foam?

A cat vomiting up white foam could be a symptom of any number of various diseases or conditions. There are numerous underlying causes for cats vomiting in general. No matter what the vomit looks like, a vomiting cat should be seen by a veterinarian for an exam and diagnostic tests to determine what is wrong and be given the necessary treatment.

Causes of Vomiting in Cats

1. Hairballs

When cats groom themselves, they will inevitably swallow some of their fur. While some fur might pass into the stool, larger amounts of fur generally don’t digest well and irritate the stomach. Cats will vomit up the fur, usually in a wet clump called a hairball. Some cats will vomit once or even a few times before they produce the hairball. This vomit before the hairball is often a white foam or clear liquid substance. Depending on if the cat has recently eaten or not, it may have bits of food in it as well.

2. Gastritis

Gastritis is irritation and inflammation of the stomach. This typically occurs when a cat has eaten a substance that upsets the stomach. This could be a foreign object, plants, toxic material, or abnormal food. It can sometimes happen from a diet change or too many treats. Vomit from gastritis could have food present if the cat recently ate, or it could consist of bile, foam, or liquid.

3. Indigestion

Indigestion can occur when a cat’s stomach acid builds up and irritates the stomach. This often happens when the cat has skipped a meal or goes too long without eating. The irritation of the stomach can cause vomiting of white or yellow foam, bile, or liquid.

4. Gastrointestinal Obstruction

A gastrointestinal obstruction occurs when a cat eats an abnormal object or material that becomes stuck in the GI tract and can’t be vomited up or passed in the stool. When something is stuck, a cat will try to vomit it up, and the resulting vomit is often foam, liquid, or bile. GI obstructions are emergencies that often require surgery to remove the foreign object.

5. Eating Too Fast

It is not uncommon for a cat to eat too fast, resulting in vomiting or regurgitation. Usually, this vomit contains undigested food with some foam or liquid.

6. Inflammatory Bowel Disease (IBD)

IBD occurs when there is inflammation of the gastrointestinal tract. When the inflammation is in the upper GI tract, it often causes vomiting. The cause could be poor digestion, food allergies, parasites, autoimmune disease, cancer, or other GI tract diseases.

7. Pancreatitis

Pancreatitis is the inflammation of the pancreas with various causes but can also happen without a known cause. The pancreas produces hormones and digestive enzymes. When it becomes inflamed, this disrupts hormone and enzyme production, causes toxin build-up, and can involve inflammation in surrounding organs such as the liver, stomach, and intestines. Cats with pancreatitis can have abdominal pain, lethargy, inappetence, vomiting, and diarrhea.

8. Kidney Disease

Kidney disease in cats is common, especially as they age. It is typically a chronic kidney disease, although acute kidney injury can occur from toxins. Kidney disease causes kidney function loss, which causes toxins to build up in the blood because the kidneys can’t filter them out. Toxins in the blood can induce ulcers in the stomach and nausea, both of which might make the cat vomit. This vomit is often liquid, foam, or bile.

9. Metabolic Diseases

Aside from kidney disease, other metabolic diseases such as diabetes or hyperthyroidism can cause vomiting.

10. Parasites

Many gastrointestinal parasites can affect cats. If there is a substantial load of parasites, it can irritate the stomach and intestines and cause vomiting. Sometimes the cat will even vomit up a worm. Some of the most common types of parasite infections in cats are tapeworms, hookworms, roundworms, and whipworms.

Diagnosing Vomiting in Cats

A vomiting cat should be taken to a veterinarian to find the cause of the vomiting. Your veterinarian will start with obtaining a thorough history and performing a physical examination. Other tests include fecal tests to check for intestinal parasites, bloodwork to screen for metabolic disease and other abnormalities associated with vomiting, and imaging. 

Imaging could include abdominal radiographs (x-rays) or an abdominal ultrasound. Imaging is done to look for foreign objects, signs of GI obstruction, masses, or inflammation in the GI tract. Images can also sometimes detect abnormalities in other organs such as the liver, bladder, or kidneys that could cause vomiting. 

If the source of the vomiting still isn’t found, more advanced diagnostics are performed, such as biopsies, endoscopy, or exploratory abdominal surgery.

Treating Vomiting in Cats

There is no good at-home treatment for vomiting in cats. A veterinarian should treat a vomiting cat because different causes of vomiting require different treatments. Your veterinarian will often provide fluid therapy either subcutaneously or intravenously and anti-nausea medications. Other medications, diet therapies, and supplements may also be needed.

What to Do if Your Cat is Vomiting

While many cat owners think vomiting might be normal, any cat that is vomiting should be seen by a veterinarian. This is especially true if the cat is vomiting more than once per week, vomiting several times in a day, there is blood in the vomit, or if the cat has other symptoms such as lethargy, inappetence, diarrhea, abdominal pain, or any other abnormalities.