Cat vomiting often: what is normal and what is not

Reading time 6 min · Level 1: Why the symptom happens

The short answer: A cat vomiting now and then is common. A cat vomiting often is not, not even when it is "just hairballs". If your cat vomits more than once or twice a month, it is time to have a vet examine it. The most common explanations are eating too fast, hairballs, food changes and parasites. But repeated vomiting is also one of the most common signs of chronic inflammation of the gut and of disease in the kidneys, liver or pancreas. If your cat vomits blood, vomits many times in one day or stops eating, it should see a vet straight away.

How often is often?

Many cat owners have got used to a hairball on the rug every so often and count it as part of living with a cat. That is understandable, but vets see it differently. Evidensia states plainly that it is not normal for a cat to vomit often¹. The Swedish insurer Dina Försäkringar puts the limit at more than once or twice a month, at which point you should contact a vet³.

Why are vets so particular? An American study reviewed 100 cats with chronic vomiting, diarrhoea or weight loss in which ultrasound had shown a thickened intestinal wall. In 99 of them, tissue samples revealed chronic small bowel disease, most often chronic enteritis or intestinal lymphoma. The authors concluded that repeated vomiting in cats should not be regarded as normal, whatever explanations the owner has been given⁵. The cats in the study had already been selected because something showed on ultrasound, so the figure does not apply to every cat that vomits. But it shows why a pattern is worth taking seriously.

Common causes

1. The cat eats too fast. If the food comes up almost immediately, often whole and undigested, the cat has usually gulped it¹. Common in households with several cats competing for the bowl.

2. Hairballs. Cats swallow hair when they groom, and some of it comes back up¹. But a review in the Journal of Feline Medicine and Surgery notes that frequent hairballs in a shorthaired cat are usually a sign of something else: that the cat is swallowing more hair than normal or that the stomach and gut are moving less well. Itching, fleas and food intolerance are common underlying causes⁴.

3. Food changes or food sensitivity. Sudden changes in diet can irritate the stomach¹.

4. Parasites and infections. Intestinal worms, viruses and bacteria can cause vomiting, often together with diarrhoea¹. Cats that hunt small birds can pick up salmonella².

5. Chronic inflammation of the stomach and gut. If the vomiting has gone on for more than two to three weeks, the cause may be inflammation of the stomach and intestine. The diagnosis is usually made by endoscopy, where small tissue samples are taken and examined under a microscope².

6. Disease in other organs. Kidney failure, liver disease, diabetes and pancreatitis can all cause vomiting. Blood tests and ultrasound are the route to a diagnosis².

7. Something the cat has swallowed. String, earplugs and small toys can get stuck in the gut². Lilies and poinsettias are poisonous to cats¹. Stress can also affect digestion¹.

When to see a vet

Straight away, the same day if your cat:

• vomits blood or pink fluid¹
• vomits many times in one day, five to six times or more, or in large amounts⁶
• cannot keep water down, or is lethargic, low or seems to have a painful belly⁶
• may have swallowed an object, such as string, or something poisonous¹
• keeps vomiting for more than a day⁶
• has stopped eating. Cats tolerate going without food worse than dogs, and even one day without food can harm their health¹

Book an appointment within a few weeks if your cat vomits more than once or twice a month³, often brings up hairballs⁴, is losing weight or has become fussy with food. Take your notes along. They are often the most useful thing the vet gets.

What you can do yourself

Keep a diary. Date, time, what came up (food, hair, froth, fluid) and how long after a meal. Two months of notes say more than a memory that the cat "vomits sometimes".

Weigh your cat. Once a week on the same scales. Weight loss is rarely visible to the eye until it has gone a long way.

Slow down a fast eater. Smaller, more frequent meals, a puzzle feeder or separate feeding spots if you have several cats. Smaller, more frequent meals also help a cat that vomits yellow froth on an empty stomach¹.

Brush and change gently. Brush your cat regularly, especially if it is longhaired. Avoid sudden food changes¹.

After a single vomit in a bright cat. Reduce food for a short period, no more than 12 to 24 hours. Then give teaspoon-sized amounts of easily digested food mixed with water. If the cat keeps it down for two hours you can give a little more. Make sure fresh water is always available⁶.

Make your home safe. Put away string, hair ties and poisonous plants.

Frequently asked questions

Is it normal for a cat to vomit hairballs?

Now and then, yes. Often, no. Frequent hairballs in a shorthaired cat usually point to an underlying cause, such as itching or a stomach that is not working as it should.

Why does my cat vomit right after eating?

Often because it ate too fast. If it happens again and again despite smaller portions, or the food comes up long after the meal, your vet should examine the cat.

My cat vomits but seems fine. Do I need to do anything?

After a single vomit it is often enough to keep an eye on things and offer easily digested food in small amounts. If it happens more than once or twice a month, it is time for an examination, even if the cat seems well.

Why does my cat vomit yellow froth?

Often because the stomach is empty and stomach acid or bile irritates the lining. Smaller, more frequent meals usually help. If it continues, contact your vet¹.

That was the short answer. If you have a question about your own pet, email us at info@herbiovet.se. We reply within one working day.