Vomiting in Cats: Common Causes and When to Worry

Vomiting, regurgitation, or a hairball

It helps to notice how the material comes up. In true vomiting, the cat usually drools, retches, and heaves with clear effort from the belly before food or fluid comes out. The material may be partly digested, or it may be yellow bile or clear foam.

Regurgitation looks different. It is passive, with little or no heaving, and it often happens soon after eating. The food usually comes back undigested, sometimes in a tube shape. Cats that eat too fast sometimes bring a meal straight back up this way. Regurgitation can also point to a problem with the esophagus, the tube that carries food to the stomach, so tell your vet which one you saw. A short phone video can help.

Hairballs form because cats swallow loose hair when they groom. Hair cannot be digested, so it collects in the stomach until the cat brings it up after a bout of hacking. A hairball usually looks like a slim, damp tube of hair, and it may be stained by bile. An occasional hairball is common, especially in long-haired cats. Frequent hairballs, or hacking and retching that bring nothing up, are a reason to see the vet.

Common causes

Irritation of the stomach lining, called acute gastritis, is one of the most frequent reasons for sudden vomiting. Spoiled food, table scraps, plants, some medicines, infections, and parasites can all set it off. The cat may vomit several times, drool, and seem uncomfortable or uninterested in food. Mild cases often settle within a day or two. Other short-lived causes include eating too fast or too much, a sudden change of food, and hairballs.

Some causes are more serious. Swallowed objects, especially string, thread, yarn, or fabric, can block or damage the intestines. Poisons can cause vomiting, and lilies are a particular danger to cats. Infections such as feline panleukopenia can cause it too, and so can pancreatitis, liver disease, and a blocked bladder.

When vomiting keeps coming back over weeks or months, the list changes. Common causes then include inflammatory bowel disease, food intolerance or allergy, intestinal parasites, constipation, kidney disease, an overactive thyroid, diabetes, and intestinal tumors. Several of these are more common in middle-aged and older cats.

When it is an emergency

Call your veterinarian or an emergency clinic right away in these situations.

• Repeated vomiting over a few hours, or retching that brings nothing up
• Blood in the vomit, which may look red or like coffee grounds
• Vomiting with weakness, hiding, or a painful or swollen belly
• Vomiting with fever or diarrhea
• A known or suspected swallowed object, such as string or a toy part
• Possible contact with lilies, human medicines, antifreeze, or another poison
• Straining in the litter box while passing little or no urine

Young kittens, elderly cats, and cats with an existing illness can get worse faster, so it is best to call the vet early if they vomit.

Lilies deserve a special warning. True lilies and daylilies can cause fatal kidney failure in cats. A bite of a leaf, pollen licked off the fur, or water from the vase can be enough. Drooling, vomiting, low energy, and loss of appetite are often the first signs. Treatment works best when it starts early, so call your vet or a pet poison hotline without waiting for more signs.

If you see a string hanging from your cat's mouth or rear, do not pull on it. Call your vet. String in the gut can saw through the intestinal wall as the intestines move.

When to book a vet visit

Many cases are less urgent. They still deserve attention if they continue. Vets generally advise a checkup if a cat vomits more than about once a week, if vomiting lasts more than a day or two in a cat that otherwise seems well, or if you notice weight loss, a change in appetite, more drinking than usual, or diarrhea. Some owners think regular vomiting is simply normal for cats. It is common, and many causes of chronic vomiting can be treated once they are found.

Appetite matters a great deal in cats. A cat that refuses food for more than a day should be seen, even if the vomiting seems mild. Cats that go without eating, especially overweight cats, can develop hepatic lipidosis, a serious form of fatty liver disease.

How vets find the cause

The vet will start with questions. Useful details include when the vomiting started, how often it happens, what the vomit looks like, how it relates to meals, any recent change of food, plants or objects the cat could reach, medicines, and whether the cat is eating, drinking, and using the litter box normally.

After a physical exam, the vet may suggest blood tests, a urine test, and a stool test for parasites. X-rays or an ultrasound can show swallowed objects, blockages, and changes in the organs. For long-term vomiting, the vet may recommend small tissue samples from the stomach or intestine, taken with an endoscope or during surgery. These samples help tell inflammatory bowel disease apart from tumors and other conditions.

Treatment and care at home

Treatment depends on the cause. For a mild, short bout of stomach upset, vets often suggest resting the stomach for a short time and then offering small, frequent meals of a bland, easily digested food, before slowly returning to the usual diet. Ask your vet how long to wait and how to offer water. Do not keep a cat without food for long on your own.

Cats that are dehydrated or vomiting often may need fluids given under the skin or through a drip, along with medicine to control nausea and vomiting. Other treatments target the cause. Examples include deworming for parasites, a diet change for food intolerance, endoscopy or surgery to remove a swallowed object, and long-term care for kidney disease, thyroid disease, or inflammatory bowel disease.

Do not give human medicines for vomiting unless your vet prescribes them. Several common human painkillers are poisonous to cats, even in small amounts. Hairball remedies are also best used under a vet's guidance.

Prevention

A few simple habits lower the risk of many common causes.

• Brush your cat regularly, especially if it has long hair, to reduce hairballs.
• Change to a new food gradually over several days.
• Feed measured meals. For cats that gulp their food, smaller meals or a slow-feeder bowl may help.
• Keep lilies out of the home, and store medicines, cleaning products, and antifreeze out of reach.
• Put away string, thread, yarn, and ribbon after play.
• Keep up with the vaccinations and parasite control your vet recommends, and book regular checkups as your cat gets older.

Rescued cats and other pets in the home

Vomiting is a sign, and some of the illnesses behind it can spread. Feline panleukopenia is a highly contagious virus. Cats catch it from infected cats, their feces and secretions, and contaminated objects, and the virus can survive in the environment for more than a year. Young, unvaccinated kittens are at the highest risk, and vaccination gives solid, long-lasting protection. Cat feces can also carry roundworms, hookworms, and other germs that can make people sick. Wash your hands with soap and water after cleaning the litter box.

Newly rescued and newly adopted cats may vomit more at first. They may carry intestinal parasites, and the stress of a move and a new diet can upset the stomach and reduce appetite. At Paw Squadron, the first stops after every rescue are the vet and a bath, with a checkup, deworming, and treatment against fleas and other parasites. Every cat is checked, treated, vaccinated, and microchipped before adoption.

In the first days at home, keep your new cat on the food it already knows and switch slowly if you want to change it. Watch appetite closely, and contact your vet if the cat vomits repeatedly or stops eating. If you have questions about a cat you adopted from us, see our FAQ or send an adoption inquiry.