Why is my cat throwing up? Common causes and warning signs

Is it normal for cats to vomit?

Many people think cats just vomit "because they do". An occasional hairball can happen, especially in long-haired cats, but vets warn that regular vomiting, for example once a week or more, isn't normal and deserves a checkup. Many feline illnesses start with occasional vomiting that we overlook.

Vomiting or regurgitation

They're different. With vomiting, the cat heaves with its belly, you hear a characteristic sound and digested food or liquid comes up. With regurgitation, food comes up effortlessly, almost whole and tube-shaped, soon after eating. Telling your vet which one you see helps a lot in finding the cause.

The most common causes

• Hairballs: while grooming, cats swallow hair that sometimes builds up. It comes out as a cylinder of hair with some fluid.
• Eating too fast: especially in multi-cat homes. The food comes back up almost whole soon after a meal.
• Sudden food changes or eating something that disagrees with it.
• Toxic plants or substances: many houseplants cause vomiting. Read Toxic plants for cats.
• Foreign objects: string, ribbon, hair ties or small toys. A swallowed string is an emergency.
• Intestinal parasites, especially in kittens.
• Illness: inflammatory bowel disease, kidney, liver or thyroid problems, diabetes or pancreatitis, among others. These are more likely in older cats.

Warning signs: see the vet

Call your vet if your cat:

• Vomits several times in one day or can't keep even water down.
• Has blood in its vomit or vomit that looks like coffee grounds.
• Is lethargic, hiding or hasn't eaten for more than 24 hours.
• Has diarrhea, fever, belly pain or is losing weight.
• May have swallowed string, a toxic plant, a medicine or a cleaning product.
• Is a kitten, a very old cat or has a known medical condition.
• Is a male that also goes in and out of the litter box without peeing: it may be a urinary blockage, a serious emergency.

What to do after a single vomit

If it was a one-off and your cat stays active, eats and acts normally, you can watch it. Remove food for a few hours but leave fresh water. Then offer a small amount of its usual food. If it vomits again or you notice any warning sign, call the vet. Don't give human medicines: many are very toxic to cats.

How to prevent hairballs

• Brush it several times a week, and daily if it's long-haired or shedding.
• Ask your vet about hairball-control foods or supplements.
• Offer cat grass, which helps them bring up hair.
• If it overgrooms until bald patches appear, itching or stress may be behind it: get it checked.

If it eats too fast

Use a slow feeder or a food-dispensing toy, split its portion into more small meals a day and, if you have several cats, feed them in separate places so they don't compete. Work out the right portion with the daily food tool. Always change foods gradually, over a week or more.

Keep a vomiting diary

If your cat vomits now and then, note the date, time, what it ate beforehand and what the vomit looked like (hair, food, liquid, foam). After a few weeks, that log gives your vet very valuable information for finding the cause, especially if vomiting increases or changes.

Make your home safer

Put away string, ribbon, hair ties and plastic bags, check your plants with our Is it toxic? tool and keep cleaning products and medicines out of reach. A curious, bored cat explores more, so a few minutes of daily play also help.

Frequently asked questions

How many hairballs are normal? An occasional one can happen, but if they're frequent, check with your vet.

Why does it vomit white or yellow foam? It often happens on an empty stomach. If it keeps happening, see your vet.

Why does it vomit right after eating? Often from eating too fast. Try a slow feeder and smaller portions.

Should I bring a sample or photo of the vomit? A photo can help your vet a lot.

This article is for information only and does not replace a visit to your vet.