cat throwing up clear liquid and foam
Cat Health and Wellness

Why is My Cat Throwing Up Water and White Foam?

Your cat bringing up white, foamy vomit can be an alarming sight. But it’s important to determine if your cat is purging its stomach constantly or occasionally. Other related symptoms are also key to an accurate diagnosis.

White foam usually occurs because the cat’s stomach or intestines have become inflamed. Furballs, parasites, and food allergies are common causes of inflammation. Occasionally, foamy cat vomit is linked to other organs, such as the pancreas (pancreatitis).

If you want to prevent your cat from vomiting white fluid in the future, you should try to improve their gastrointestinal (GI) health (stomach and intestines). We’ll explain why most cases of foam vomiting in cats occur, what to do, and how to support your feline’s GI health.

Normal Reasons Why Your Cat Is Vomiting White Foam

If your cat is throwing up regularly, this is not considered ‘normal.’ However, most cats will vomit from time-to-time, and throwing up is not necessarily a sign of illness.

Vomiting may sometimes be a behavioral issue, or it could be your cat’s way of expelling toxic substances. Cats throw up for the following reasons:

Running Off Too Quickly After a Meal

This can happen if the feeding area doesn’t feel safe for your cat. Kittens may also run off too soon after a meal because they enjoy playing.

Eating Too Fast or Overeating

Overeating can sometimes be caused by an underlying illness, but it may also be caused by an irregular feeding schedule. Also, if multiple cats are sharing the same food bowl, they’ll try to eat the meal faster.

Eating an Indigestible Substance

Cats may throw-up substances that their stomachs cannot process effectively. Cats eat grass, for example.

Cats do not have the right enzymes to process grass, so they’ll usually regurgitate it. Some specialists believe cats eat grass on purpose to help dislodge fur, bones, or things from their stomachs.

So, cats throw up for various reasons, not just because they are physically ill. Nevertheless, if it’s happening regularly, you should investigate why.

Should I Be Worried That My Cat is Vomiting?

Although occasional vomiting is not too concerning, you should seek immediate treatment for your cat in the following scenarios:

  • Your cat has been vomiting for more than 24 hours
  • Your cat is unable to eat or drink the day after vomiting (though it’s normal for cats to refuse food for up to 12 hours after vomiting)
  • Breathing difficulties
  • Your cat tries to vomit, but nothing comes out
  • Diarrhea and vomiting at the same time
  • Blood (brown vomit) or green bile in the vomit
  • Your cat is throwing up white foamy liquid. This is especially important if it has occurred more than three times in 24 hours and/or has lasted longer than 24 hours)

If your cat is throwing up white liquid, it’ll need to be checked by a vet. A variety of diseases and lifestyle factors can cause white foamy vomit and these range in severity from mild to severe.

cat throwing up saliva foam

Why Is My Cat Throwing Up White Foamy Liquid?

Your cat probably has an issue with their gastrointestinal (GI) tract. The GI tract consists of the mouth, teeth, tongue, pharynx, esophagus, stomach, small intestine, and large intestine. If any part of the GI tract becomes inflamed or infected, your cat may throw up a foamy white substance.

If your cat is vomiting up white foam, your vet may diagnose ‘Gastritis’ or ‘Gastroenteritis.’ These broad-sweeping terms mean that a part of your cat’s GI tract has become inflamed or infected. To be more specific:

  • Gastritis – This refers to an inflammation or infection of the stomach.
  • Gastroenteritis – This refers to an inflammation or infection of the stomach and intestines.

GI problems can be acute (sudden and temporary), or they can be chronic (ongoing). This means some instances of vomiting can be cured quickly, whereas others may require long-term care and prevention.

Gastrointestinal Tract Obstruction

For your cat to stay healthy, food and water must pass through the GI tract efficiently. If there is an obstruction, your cat won’t be able to absorb vital nutrients from their food, and may become dehydrated.

Obstructions can form in the stomach (gastric outflow obstructions) or the intestines. If your cat develops an obstruction in their intestines, it may be due to intussusception.

According to AVCA, intussusception occurs when part of the intestine slides into the other, causing a blockage. Here’s what causes blockages:

  • Eating foreign bodies – this is the most common cause. Cats may swallow string, ribbon, bits of plastic or anything they can get their paws on. Cat hair can also cause a blockage.
  • Tumors (cancerous or benign) – these can press on the GI tract and cause an obstruction
  • A hernia
  • Injury
  • Parasites

If your cat’s obstruction is in the stomach and it cannot digest food, it may throw up some hydrochloric acid in its vomit.

This may have a mucus-like texture and will usually have a slight yellow tinge to it. Obstructions in the intestines can cause foamy vomit, but also diarrhea, abdominal swelling, and lethargy.


Cats groom themselves daily using their tongue, and some of the hair inevitably enters the gastrointestinal tract. Most hair will pass through in your cat’s poop, but some may accumulate in the stomach. If too much hair collects in the stomach, this will lead to stomach inflammation.

When your cat’s stomach is inflamed, it will try to ‘cough up’ the furball. Some furballs are difficult to bring up so your cat might vomit bile or watery liquid for several days before the hairball makes an appearance.

Furballs can become lodged in the cat’s GI tract, causing an obstruction. You’ll probably need a vet’s help to dislodge the furball. This condition can become life-threatening if the obstruction is not removed.

Although we think it is “normal” for cats to vomit up furballs, there is limited evidence to suggest that feral cats have this problem. Coughing up furballs is probably not as “natural” as we think it is, so we should try to prevent this from happening.

Food Allergies

If your cat does vomit due to an allergy, the vomit is often milky or foamy in texture. This is because the stomach lining is inflamed. In addition to white foam, you’ll probably also see undigested bits of food in its vomit.

If your cat has an allergic reaction, you’ll probably see some of the following symptoms:

  • Diarrhea
  • Intensive scratching and/or hair loss on the head or tail
  • Weakness and lethargy
  • Cat acne

These symptoms can be caused by other things so it can be hard to diagnose food allergies. Indeed, there is no genuinely reliable diagnostic test for allergies, but there are ways you can manage them.

Some common cat allergies include the following:

  • Chicken
  • Fish
  • Eggs
  • Dairy (most cats are also lactose intolerant)
  • Grains (less common)

Cats tend to be allergic/intolerant to a specific protein rather than a grain, though some cats are occasionally affected by grains.

If you think your cat might be allergic to something in their diet, there are a few things you can do to help:

  • Hydrolyzed Protein – Buy a cat food that is made with hydrolyzed protein. This means the protein has been broken down into small pieces making it digestible for most cats.
  • Hypoallergenic Cat Food – There are specialist cat foods that are made with fewer ingredients, so they are less likely to stimulate an allergic reaction. The manufacturers switch the allergenic ingredients for ingredients that most cats can digest.

It’s a good idea to notify your vet of any dietary changes so they can monitor your cat’s progress with you.

cat throwing up white mucus

Eaten Something That’s Toxic

If your cat has vomited white liquid several times in quick succession, there’s a chance they’ve eaten something toxic.

Similarly, if they are gasping and heaving – but only a small amount of mucus is coming out – they might have ingested something harmful.

Many owners don’t realize how many ‘hazards’ there are in and around the home. Cats can usually sense what is edible and what is not, but that’s not always the case. The following household products can be toxic for cats:

  • Caffeine – Most of us tend to leave bits of coffee or tea at the bottom of our cups. If you leave these cups lying around and don’t provide your cat with fresh water, it may start drinking your leftovers.
  • Garlic and Onion – Most cats find it very hard to process these vegetables, so you shouldn’t allow them to eat your leftovers. The consumption of spice is toxic to cats.
  • Chocolate – Most people know that it is deadly for dogs, but chocolate can cause severe gastritis in cats, too.
  • Alcoholic Drinks – Again, cats may drink an alcoholic beverage if that’s the only fluid available.
  • Plants – Especially daffodils, foxgloves, and eucalyptus.

If your cat has ingested something toxic, you may see additional symptoms such as hyperactivity, disorientation, yowling, or diarrhea.


Lots of parasites can find their way into the GI tract, especially into the large and small intestine.

According to Cornell, up to 45% of cats will experience ‘gastrointestinal parasitism’ during their lifetime. Parasites can cause diarrhea, lethargy, and vomiting.

The following parasites are particularly likely to cause vomiting:

  • Roundworms – Roundworms live in the intestines, and they can grow to become very large if not treated. A cat with roundworms will have a voracious appetite. It will most likely suffer from diarrhea and vomiting. If your cat has roundworms, you’ll probably be able to see evidence in their feces or the liquid they throw up.
  • Coccidia – This parasite is very common, and most cats will contract it during their lifetime. However, if kittens develop it, they may start throwing up violently. A kitten with Coccidia can become dehydrated very quickly if they don’t receive treatment.
  • Fleas – Cats who have fleas are more likely to overgroom. The more they groom, the more fur will end up in their stomachs. It’s no surprise that cats with fleas often cough up more furballs.
  • Stomach Worms – These are quite rare in the US, but cats do occasionally catch them. They can cause persistent heaving/gagging and foamy vomit.

If parasites are left to fester, they’ll lead to weight loss, a poor coat, and mood changes.

Irritable Bowel Syndrome

If your cat is vomiting white mucus, and it is having problems going to the toilet (constipation, bloating and/or diarrhea), your vet might diagnose Irritable Bowel Syndrome (IBS).

This condition occurs when the bowels become inflamed, but vets don’t always know why this occurs. IBS is a syndrome, so it’s a collection of symptoms that can be caused by various factors.

The GI diseases (allergies, parasites, etc.) could lead to a diagnosis of IBS in some cats, especially if these diseases do not respond well to treatment.

However, it’s important to say that IBS is not always caused by gastrointestinal issues.

Some scientists believe mental distress is one of the leading causes of IBS in cats. This makes sense because we know cats can become easily stressed if their environment is inadequate or they feel threatened in any way.

So, if you want to prevent conditions such as IBS, try to create a calm and relaxing home for your cat.


Although most cases of vomiting are linked to the GI tract, vomiting can occasionally be a sign of pancreatitis (inflammation of the pancreas). The pancreas is a small organ, but it plays a key role in digestive health.

The pancreas releases a liquid that helps the cat to digest fats, proteins, and carbohydrates. In some cases, the pancreas doesn’t release enough liquid (exocrine pancreatic insufficiency), or in some cases, it produces too much liquid (pancreatitis). If the pancreas produces too much of this liquid, it can seep back into the pancreas – causing inflammation.

Either way, issues with the pancreas will usually cause vomiting. They may vomit undigested food, mucus, and white liquid.

Scientists aren’t exactly sure what causes pancreatitis. Nevertheless, there is research to suggest that ingesting insecticides, consuming too much fat in the diet, parasites or physical trauma may cause pancreatitis in cats.

Cats with pancreatitis often become lethargic and refuse food. They can become dehydrated very quickly so if left untreated, this condition can be life-threatening. As part of the treatment, your vet may prescribe enzymes to help your cat break down fats, proteins, and carbs in the GI tract.

Cat Is Throwing up Foam and Not Eating

Although vomiting foam isn’t always a sign of severe illness, it can quickly lead to a severe secondary condition, such as dehydration.

According to the Blue Cross, you should care for a cat in the following way:

  1. If your cat throws up, remove all food for 12 hours but provide it with clean, fresh water.
  2. If it continues to vomit, it has diarrhea or extremely lethargic, take your cat to vet.
  3. After 12 hours have passed, offer it 1 spoonful of cat food.
  4. If it eats this, keep offering it a spoonful every 2 hours until its eaten a normal portion. Return to normal feeding the next day.
  5. If your cat is unable to eat and drink anything 12 hours after it last vomited, or they’ve been vomiting on and off for more than 24 hours, it is important to see the vet. At this stage, electrolyte imbalance and dehydration become a serious concern.

A dehydrated cat may start panting, have sunken eyes, and its skin will start to ‘tent.’ You can check if your cat’s skin is tenting by gently pinching the skin at the back of their neck. If the skin does not ping back into place immediately, this suggests your cat is dehydrated.

If your cat is throwing up foam once now and then, this indicates poor GI health. While it is probably not life-threatening, you should take steps to improve your cat’s digestive health.