Cat Vomiting: Causes, Hairballs and When to Call a Vet

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Every cat owner knows the sound. A cat that vomits once and then bounces back to normal is not unusual, but vomiting is also one of the most common signs of illness in cats. Knowing which is which can save your cat from a serious problem, and spare you an unnecessary panic.

Is occasional vomiting normal?

Veterinarians often say that frequent vomiting is common in cats, but not normal. A cat that brings up a hairball every few weeks is probably fine. A cat that vomits weekly, or more than once in a day, has a reason, and the reason is worth finding.

Common causes

Eating too fast. Cats that gulp food, especially in multi-cat homes, may vomit soon after. Slow feeders and smaller, more frequent meals help.

Hairballs. Cats swallow hair when grooming, and some of it forms a clump that is vomited up. Brushing helps, as explained in how to brush a cat. Frequent hairballs can signal skin disease, overgrooming or digestive trouble.

Diet changes or intolerance. Sudden switches, rich treats or table scraps can upset the stomach.

Foreign objects. Cats swallow string, ribbon, hair ties, toys, plastic and thread. Linear foreign bodies can cut the intestine and are an emergency.

Toxins and plants. Lilies, certain houseplants, chemicals, medications and foods such as chocolate and onions are dangerous. See toxic houseplants for cats and lilies and cats.

Parasites. Intestinal worms and some infections.

Chronic disease. Kidney disease, hyperthyroidism, diabetes, liver disease, inflammatory bowel disease, pancreatitis and cancers can cause vomiting.

Infections. Viral and bacterial illnesses.

Stress. Moving, new pets or travel may trigger it.

What the vomit can tell you

Take a photo to show your vet.

What to do for a single episode

If your cat vomits once, seems bright and has no other signs:

1. Remove food for a couple of hours, but keep water available.
2. Offer a small amount of the usual food and watch.
3. Check for anything your cat might have chewed or swallowed.
4. Monitor for repeat vomiting, lethargy or appetite changes.
5. Do not give human medication, since many are toxic to cats.

Do not fast a cat for a long time. Cats that stop eating can develop a serious liver condition called hepatic lipidosis, particularly if overweight.

When to call the vet

Contact your vet the same day if:

• Vomiting happens more than once or twice in a day, or weekly
• Your cat refuses food for more than a day
• You see weight loss, diarrhea, increased thirst or lethargy
• Your cat is a kitten, a senior or has a chronic condition

Go to an emergency clinic right away if you see:

• Repeated vomiting or unproductive retching
• Blood in the vomit
• A swollen or painful belly
• Collapse, weakness or breathing trouble
• Suspected swallowed string, toxins, lilies or medication
• Vomiting along with straining in the litter box. See signs of a urinary blockage in cats.

Our emergency warning signs guide lists more red flags, and the US vet directory can help you find a clinic.

How vets investigate

A vet will ask about diet, behavior and access to hazards, and examine your cat. Tests may include bloodwork, urinalysis, fecal tests, X-rays, ultrasound and sometimes endoscopy. Treatment depends on the cause, and may include anti-nausea medication, fluids, diet changes or surgery. Costs are covered in cat vet visit costs.

Reducing vomiting at home

• Use a slow-feeder or puzzle feeder for fast eaters.
• Split meals into smaller portions.
• Brush regularly and treat hairball-prone cats with advice from your vet.
• Switch foods gradually over seven to ten days.
• Keep string, ribbon and small objects out of reach.
• Review portions with how much should I feed my cat.

Vomiting in kittens and seniors

Kittens can become dehydrated and hypoglycemic quickly, so any vomiting that repeats or comes with diarrhea, lethargy or refusal to eat needs a call to the vet the same day. Senior cats are more likely to have chronic conditions such as kidney disease and hyperthyroidism, so new or repeated vomiting in an older cat should be investigated even if the cat seems otherwise well. Bring a list of changes in appetite, thirst and weight to the visit.

Long-haired cats and hairballs

Long-haired cats such as Persians or Maine Coons produce more hairballs. Regular combing, hairball-control diets recommended by your vet and good hydration help. Hairballs that cannot be passed and cause repeated retching, with no stool, can signal a blockage and need prompt attention.

This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.