Cat Vomiting: Causes and What to Do [Jarosław Sałek, DVM]

Medically reviewed by: Kinga Wojtczak, Doctor of Veterinary Medicine, specialist in canine and feline diseases

What should you do when your cat is vomiting, and what causes vomiting? You will find the answers in this article by Jarosław Sałek, Doctor of Veterinary Medicine. From this article, you will also learn when cat vomiting can be a sign of a serious disease and how to recognize the condition by what the vomit looks like. I will also explain what you can do when your cat is vomiting. Vomiting is very common in animals, but it should not always be treated as a sign of disease. Whether vomiting is something serious depends on the circumstances in which it occurs and on what the vomit contains.

What is vomiting?

Vomiting is an active process preceded by warning (prodromal) clinical signs, and it consists of three phases:

1. First phase—nausea: often associated with excessive salivation, restlessness, yawning, attempts to swallow and lip licking.
2. Second phase—retching: attempts to vomit with contractions of the abdominal muscles, but without bringing anything up.
3. Third phase—actual vomiting: the stomach contents are forcefully expelled, accompanied by strong contractions of the abdominal muscles.

This process can take the form of acute vomiting or chronic vomiting. Chronic vomiting is vomiting that lasts more than 3 weeks; acute vomiting lasts for a shorter time.

What causes vomiting?

Vomiting can be caused by various factors.

The most common causes of vomiting in cats are:

• hairballs,
• parasites,
• dietary errors,
• bacterial and viral diseases of the digestive tract,
• vomiting in cats can also be a secondary sign of other diseases.

So, as you can see, vomiting in cats is not always linked to a primary disorder of the digestive tract. Importantly, this sign should be distinguished from regurgitation and coughing in cats.

How does vomiting differ from regurgitation?

Clinical sign	Regurgitation	Vomiting
Abdominal contractions	Absent	Present
Food bolus in the cervical (neck) part of the esophagus	May be present	Absent
Warning (prodromal) signs: retching and nausea	Absent (rarely drooling)	Present
Type of material brought up	Undigested, no bile, variable pH, cylindrical (tube) shape	May be partly digested (depending on the time between eating and bringing it up), bile may be present, pH <5, variable shape
Time of expulsion	Variable	Variable
Pain when swallowing	May be present	Absent

An act similar to vomiting can be gagging, also known as retching. These are repeated attempts to vomit without bringing anything up. In fact, they should therefore be treated as vomiting. Note that in some cases, even with a good history, a veterinarian has difficulty distinguishing retching and regurgitation of saliva from coughing and/or coughing up sputum.

The most common causes of vomiting in cats (from most to least common):

• Hairballs lodged in the digestive tract (mainly long-haired cat breeds).
  Hairballs in cats are also known as bezoars.
• Gastrointestinal parasites.
• Kidney failure (mainly affects cats over 7 years of age).
• Panleukopenia (mainly affects cats up to 6 months of age).
• Dietary errors leading to gastritis (inflammation of the stomach).
• Vomiting due to damage to other organs: * pancreatitis, * liver damage, * inflammation of the gallbladder, * triaditis.
• Intestinal obstruction: * intussusception, * a foreign body in the intestines.

There are so many other causes of vomiting that it is impossible to list them all…

What cat vomit looks like

The nature of the vomit, that is, what is in the material your cat brings up, is very important. Based on what the vomit looks like, we can work toward a diagnosis.

Cat vomiting foam

If your cat is vomiting foam, it is very often caused by pharyngitis (inflammation of the throat). While the inflammation in the throat is ongoing, the mucous membrane is constantly irritated, which triggers the vomiting reflex. This reflex is short-lived, often without involvement of the abdominal muscles, and the reflex itself brings up foam, often with a small amount of saliva.

These signs are often accompanied by:

• lethargy (the cat seems depressed),
• loss of appetite.

Vomiting foam can also happen when you have triggered the vomiting reflex with hydrogen peroxide.

Cat vomiting after eating

If your cat throws up after eating, the appearance of the vomit alone can tell you a lot about its cause. The time between eating and vomiting is also important.

If the animal vomits undigested food, we may suspect:

• esophageal defects due to narrowing (stricture), e.g., after an injury,
• inflammatory problems of the upper digestive tract,
• persistent right aortic arch,
• esophageal achalasia (usually seen in dogs).

In esophageal achalasia, food that has been chewed and moistened in the mouth does not reach the stomach but is brought back up from the esophagus. This act is exactly what we call regurgitation. If the animal vomits digested food (meaning the food has reached the stomach), this may point to dietary errors.

A sudden change of food irritates the stomach lining (gastritis), which leads to more frequent and stronger stomach contractions, and as a result we see the cat vomiting. Vomiting can also be caused by eating foods that are toxic to cats. Food in the vomit may also be linked to nausea. In such situations, the food is not absorbed and the receptors responsible for the contractions that lead to vomiting are stimulated.

This sign is usually seen with kidney failure. In kidney failure, the kidney values, that is, urea (BUN) and creatinine, are elevated.

Circulating in the blood in increased amounts, these substances lead to gastritis, which results in:

• nausea,
• vomiting,
• loss of appetite.

Cat vomiting saliva

Saliva is produced by the salivary glands and released into the mouth. When your cat vomits saliva, or saliva is one of the components of the vomit, we may suspect a disease process in the upper parts of the digestive tract.

Vomiting saliva is most often caused by:

• pharyngitis,
• gingivitis,
• stomatitis (inflammation of the lining of the mouth).

These signs are accompanied by:

• bad breath,
• loss of appetite,
• drooling.

Very often, saliva is a secondary component of the vomit, while parasites are the main one.

Cat vomiting blood

Depending on what the blood in the vomit looks like, we can suspect where the bleeding is coming from. If your cat is vomiting blood that comes from the stomach, it will have the typical appearance of coffee grounds. This blood is always digested, and we call this coffee-ground vomiting.

It occurs with:

• stomach ulcers, which may develop as a result of generalized uremia,
• stomach parasites, e.g., Physaloptera,
• after treatment with anti-inflammatory drugs.

These signs are often accompanied by pain in the cranial abdomen (the front part of the belly). If we see fresh blood in the vomit, we are dealing with bleeding above the stomach. This is bright, fresh blood, which may have been brought up with esophagitis or stomatitis. In these conditions, the swollen, inflamed mucous membrane is heavily congested and tends to bleed.

Less often (although such cases do of course happen), a foreign body in the esophagus may be suspected.

Cat vomiting bile

If your cat is vomiting bile, further tests are necessary, because bile in the stomach is not a clear-cut finding. Bile is often the only content of the vomit. Strong contractions of the empty stomach and antiperistaltic movements of the duodenum (where bile is released) lead to a vomiting reflex that brings up only a thick, yellow liquid. This is bile-stained vomit.

Bile-stained vomit is caused by inflammation in the stomach, intestines or what is known as triaditis (inflammation of the liver, pancreas and intestines at the same time). This type of vomiting is a secondary sign of other diseases going on in the body, so as soon as you notice it, see your veterinarian. Later in the article, I will explain, among other things, when a cat vomits worms and what to do when vomiting appears after eating a poisonous plant.

Cat vomiting worms

With a heavy worm burden, cats very often vomit worms. A classic example is the feline roundworm, Toxocara cati. This parasite migrates through the cat's body as it develops. Its migration route includes the lungs and the trachea, and only when the worm reaches the throat is it swallowed into the digestive tract. Migration through the respiratory tract and then through the upper parts of the digestive tract is a strong trigger for the cough reflex and vomiting.

Vomited worms, whether a tapeworm or a roundworm, may also come from the stomach, after which they move on to the intestines, where they normally live.

As a reminder, the most common parasites in cats include:

• the feline roundworm,
• the feline tapeworm,
• Giardia (lamblia).

Giardia, also known as Lamblia, is a protozoan that causes inflammation of the stomach and intestines. With inflammation caused by Giardia, chronic, explosive diarrhea is seen in addition to vomiting. Remember that Giardia is a microscopic protozoan, so you cannot see it with the naked eye.

Cat vomiting hair

Cats are very clean animals. They keep themselves clean by licking their coat, which is called grooming. Grooming several times a day always means that some hair gets into the digestive tract. Small amounts of accumulated hair are often passed with the feces. However, when the amount increases, we may be dealing with hairballs or bezoars.

Bezoars are large balls of hair that often cause an obstruction and need to be removed surgically. Hairballs, by contrast, are removed from the stomach by vomiting. This active process occurs naturally in cats and serves to prevent bezoars from forming. It mainly affects long-haired cats or cats with a thick coat.

Cat vomiting after medication

Other causes of vomiting include some drugs and toxins. Toxins and substances that are swallowed directly or enter the body another way (e.g., injections) can lead to inflammation of the stomach lining. We most often see this during treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) without drugs that protect the stomach lining.

A similar condition may result from intolerance to one of the antibiotics, to a drug given by mouth or to one given by injection. In both of these cases, the drugs being used should be stopped immediately.

Cat vomiting after eating plants

You probably know that cats get everywhere and take an interest in everything around them. Unfortunately, all that curiosity increases the chance that they will eat a plant that is poisonous to cats. Plants that are toxic to cats are, unfortunately, often found in homes.

Examples include:

• oleander,
• weeping fig (Ficus benjamina),
• dracaena,
• poinsettia.

Vomiting is one of many signs that accompany damage to internal organs after eating a poisonous plant.

Foreign body in a cat's digestive tract

Decorations found in homes can also attract your kitty's interest. Cats fairly often eat material used to decorate plants or a room. Most often these are ribbons, strings and threads, which are referred to as a linear foreign body. They do not cause an obstruction, but because they lie along a longer section of the intestines, they lead to invagination and intussusception of the intestines, and one of the signs is acute vomiting.

Cat vomiting after surgery

Vomiting is not always a sign of disease. If your cat vomits after surgery, this may be caused by the sedatives used for or after the surgery. Drugs used for anesthesia disrupt the motility of the digestive tract, which can result in vomiting. In this case, it is important that the animal is placed in the right position, which will prevent it from choking on (aspirating) vomit.

Motion sickness in cats

Cats are a lucky species in which motion sickness does not cause signs as severe as in dogs. However, vomiting in cats during travel can also happen. In that case, the classic Aviomarin or Lokomotiv (motion sickness medicines for people, sold in Poland) can be given before the journey. Keep in mind, however, that this drug is poorly absorbed in cats compared with humans, and it may not have the desired effect. That is why, before a trip, it is best to get veterinary products, available from your veterinarian.

Diagnosing vomiting in cats

Diagnosing vomiting is fairly difficult in itself. By diagnosis, I mean here laboratory testing in the broad sense and a detailed history from the cat's owner. The cat's owner must be honest with the veterinarian about what the cat eats, what it may have eaten and which plants are in the home. The next step after taking the history is a blood test.

A blood test allows us to assess the animal's general condition and possibly identify the cause of the vomiting. Kidney, liver and pancreatic causes will be confirmed or ruled out. In such situations, it is a good idea to run an electrolyte panel (ionogram). It measures the levels of the main electrolytes in the body.

Remember that a significant amount of electrolytes is lost during vomiting. This leads to a fluid and electrolyte imbalance, which can only be assessed with an electrolyte panel. A fecal parasite test or ELISA tests (Giardia SNAP test) can also be done if we suspect worms in the cat.

If the blood results are inconclusive, an ultrasound scan is a very useful test. It allows us to subjectively assess motility and how the digestive tract is working, and to find a foreign body, if there is one. An equivalent test, alongside ultrasound, is a contrast X-ray study.

This test allows us to determine whether there is an obstruction somewhere in the digestive tract.

When should you see a vet?

The decision to see a veterinarian should depend on how often and what your cat throws up. It is generally accepted that a cat may bring something up once every 2 weeks, often hairballs and food that is not fully digested. Further steps and treatment depend on the cause of the vomiting, because vomiting itself is not treated. Only antiemetic drugs (anti-vomiting medication) are used.

Only after a full examination of the animal and clinical tests do we treat the primary disease that is causing the vomiting. Supportive treatment consists of fluids given intravenously (IV) or subcutaneously (under the skin), which replace the fluid and electrolyte losses caused by vomiting.

Prevention

For cats that tend to get hairballs, products that help pass hairballs in the feces are used preventively. These come as a paste, such as Bezo-Pet or Malt, or you can use a dry kibble food called Fibre. Cats with a sensitive digestive tract and stomach inflammation should eat an easily digestible food of the intestinal type.

For vomiting caused by pancreatic problems, I recommend an intestinal low fat type of food.

For liver problems—a hepatic type of food, or food prepared at home:

cooked rice with chicken and carrot, blended. Cats with kidney failure should also have their diet supplemented with products such as Rubenol or Renalvet. These help remove the kidney metabolites responsible for causing vomiting. At the same time, it is important to feed a renal diet. To protect cats from vomiting caused by a heavy worm burden, regular deworming is important.

This can be done with pastes, tablets or spot-on drops applied to the back of the neck, repeated every 3 months in cats that go outdoors and every 6 months in indoor cats. I recommend switching the deworming product from time to time, as this improves how well parasites are controlled.

Summary

So, as you can see, vomiting in cats is a common problem with various causes. The same is true in people and in dogs. It is important that you react as quickly as possible. Don't assume that vomiting only means a stomach problem, because it can be caused, for example, by parasites. On the other hand, you must not panic. Vomiting without an underlying disease also happens, but for peace of mind, it is always a good idea to get advice from a veterinarian.

Has your cat ever vomited? How did you deal with it? I would love to hear about your experience with this problem. Add a comment below the article now, and I will reply as soon as I can.

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