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Cat Vomiting: When It's Normal and When to Call the Vet

Good to know: general information, not veterinary advice. Read our disclaimer.
Photo of a tabby cat looking worried beside an empty food bowl

Short answer: an occasional vomit, especially a hairball every week or two, is common in healthy cats. Vomiting that keeps coming back, lasts more than 24 hours, or comes with other symptoms such as lethargy, blood, or diarrhea is a reason to call your veterinarian.

Few things make a cat owner worry faster than the sound of retching from the next room. Is it just a hairball, something your cat ate too fast, or the first sign of a real illness? This guide explains what is usually harmless, what deserves a phone call to your vet, and what you can do to make vomiting less likely. Everything medical below comes from two veterinary sources and five cat-health articles, all listed at the end.

Is it normal for a cat to throw up?

Healthy cats do vomit now and then, and it is often harmless. The Cornell Feline Health Center notes that the concern starts when a cat gags and throws up frequently, particularly soon after eating. A single episode in an otherwise bright, hungry, playful cat is usually something to watch rather than panic about.

Two questions help you sort it out quickly. First, how often is it happening? One-off events are very different from a pattern. Second, how does your cat act in between? A cat that vomits once and then eats, drinks, plays, and uses the litter box normally is in a very different situation from a cat that hides, refuses food, or seems weak.

Hairballs: the most common harmless cause

A hairball is a damp, cylindrical wad of undigested hair mixed with digestive fluids. Cornell describes bringing one up every week or two as normal. Cats swallow hair every time they groom, and most of it passes through the digestive tract without any trouble. What does not pass can come back up.

The same source adds an important warning: a cat that cannot bring hair up can end up with a clump moving into the intestines, which can cause a life-threatening blockage. So a cat that retches again and again without producing anything should be seen by a vet.

Long-haired breeds tend to swallow more hair while grooming, so regular brushing is the simplest prevention. Our grooming guides explain practical routines for specific coats: the Persian grooming routine, grooming a Turkish Angora, Ragdoll coat care, and how to stop mats in Norwegian Forest Cats.

Other common causes of vomiting

Hairballs are only one possibility. The two veterinary sources group the causes like this.

Food-related causes

PDSA lists mild stomach upset (gastritis), a change of diet, and eating something unusual among the common causes. International Cat Care says that switching a cat's food gradually helps prevent digestive upset such as vomiting and diarrhea. Its suggested method is to offer the old and new foods at the same time in separate bowls, since cats generally dislike having two foods mixed together, starting with about 75% old diet and 25% new diet. The pace depends on the cat: some adjust within 5 to 7 days, while others may take 2 to 8 weeks. If your vet has given specific instructions, those take priority.

If you are comparing diets, our guide on wet food versus dry food covers the basics of feeding a Norwegian Forest Cat.

Swallowed objects (foreign bodies)

Cats are curious, and some swallow things they should not. Cornell lists string or yarn, small objects such as paper clips or rubber bands, and spoiled food among the possible causes. International Cat Care adds that a foreign body is any non-food item a cat swallows, and that you should not assume it will pass on its own, because it often does not.

  • Linear items such as string, thread, needles, wool, yarn, string around meat, and tinsel can bunch up the intestines and make a cat very unwell. They usually require surgery.
  • Other common items include hair bands, rubber bands, toy stuffing, carpet fibers, ribbon, dental floss, and blind cords.
  • Small objects such as coins, buttons, earplugs, fruit stones, nut shells, and bottle tops can block the intestines and usually need surgical removal.
  • Cooked chicken bones can be sharp and lodge in the intestines.

Signs can include refusing food, lethargy, retching, vomiting, diarrhea, and abdominal pain. Cats often hide illness, so the only sign may be extra sleeping or less interest in interaction. Early treatment matters.

Poisonous plants and substances

Cornell lists poisonous plant leaves, human medications, antifreeze, chocolate, and onions among the substances that can make a cat vomit. International Cat Care stresses that lilies are extremely dangerous to cats: all parts are toxic, and even a small amount of leaf, flower, or pollen, or the water from a vase of cut lilies, can be fatal. Dieffenbachia, deadly nightshade, and daffodils are also listed as hazardous.

If your cat eats a poisonous plant, contact your veterinary team immediately and do not try to make your cat vomit. If possible, keep the plant label handy and note the time and any symptoms.

Parasites and digestive conditions

Cornell lists intestinal worms, constipation, inflammatory bowel disease, intestinal obstruction, and benign or cancerous growths among the possible digestive causes. Constipation is worth a special mention: International Cat Care explains that vomiting is not an early sign of it, but appears in severe cases along with a loss of appetite.

Illnesses that affect the whole body

Both sources point to metabolic and organ diseases, including kidney disease, diabetes, hyperthyroidism, liver disease, and pancreatitis. Hyperthyroidism is a good example of why a vomiting senior cat should not be ignored. International Cat Care says it usually affects middle-aged and older cats and is rare in cats under 7. Signs include weight loss despite a hungry cat that eats more than usual, increased thirst, restlessness, a poor coat, a faster heart rate, and mild to moderate vomiting. A blood test confirms it, and treatment options include radioactive iodine, daily anti-thyroid medication, surgery, or a prescription low-iodine diet. The article notes that most treated cats make a complete recovery.

PDSA also lists food allergies and medication side effects as possible causes.

When to call the vet

The two veterinary sources agree on the main warning signs. Contact your veterinarian promptly if your cat:

  • vomits more than once a week (Cornell), or more than once in a short period and seems unwell (PDSA)
  • has been vomiting for more than 24 hours, or cannot keep food or water down (PDSA)
  • is lethargic, weak, or eating less (Cornell, PDSA)
  • has blood or black dots in the vomit (Cornell, PDSA)
  • has diarrhea at the same time (Cornell, PDSA)
  • is drinking or urinating more than usual, or less than usual (Cornell, PDSA)
  • has pale gums or a painful belly (PDSA)
  • may have eaten something harmful, such as a plant, a medication, string, or a toy (PDSA)
  • is a kitten, a senior cat, or already unwell (PDSA)

If you think your cat swallowed a poison or a foreign object, do not wait to see whether it passes. Call your vet or an emergency clinic.

What to do while you watch at home

For an otherwise well cat that vomited once, PDSA suggests monitoring: keep feeding normally, make sure fresh water is available, and watch closely. Contact a vet if your cat seems unwell or vomits again.

  • Do not give human medication.
  • Do not try to make your cat vomit after a suspected poisoning.
  • Check with your vet before changing your cat's diet or withholding food. PDSA does not advise withholding food for an otherwise well cat.
  • Remove anything your cat could chew or swallow, such as string, ribbon, and hair bands.

What your vet may do

According to Cornell, the vet will usually take a detailed history, examine your cat, and may run bloodwork and a fecal test to look for toxins, parasites, and metabolic disease. If those are normal, X-rays or an ultrasound can look for masses or foreign objects, and in some cases an intestinal biopsy is used to check for cancer or inflammatory bowel disease.

Treatment depends on the cause:

  • Supportive care: intravenous or subcutaneous fluids for prolonged vomiting, then a bland, easily digested diet once vomiting stops. Anti-nausea medication may be prescribed in some cases.
  • Parasites: deworming.
  • Toxins: an antidote where one exists, or supportive care.
  • Obstructions: endoscopy under anesthesia can remove some, but many require surgery.
  • Inflammatory bowel disease: usually managed with diet, antibiotics, and/or steroids.
  • Metabolic disease: therapy directed at the underlying condition.

How to help your vet help your cat

A little preparation makes the appointment more useful. Before you go, note:

  • how often your cat vomits and how long it has been going on
  • when it happens relative to meals
  • what the vomit looks like (food, foam, hair, blood, black dots)
  • any recent change in food, treats, or routine
  • anything your cat could have chewed or swallowed, including plants
  • changes in thirst, urination, weight, appetite, or litter box habits

A short phone video of an episode, and a photo of the plant or object involved, can also help.

How to make vomiting less likely

  • Brush regularly, especially long-haired cats, to reduce the hair they swallow.
  • Change food gradually, over days or weeks depending on your cat, as described above.
  • Keep risky items out of reach: string, ribbon, yarn, tinsel, hair bands, dental floss, and blind cords. International Cat Care also recommends safe toys and regular play, which can matter more for young and indoor-only cats.
  • Remove toxic plants, especially lilies, and check labels before buying new houseplants or bouquets.
  • Keep medications and human foods secured, including chocolate and onions.
  • Book regular check-ups, particularly for senior cats, since several causes of vomiting are illnesses of older age.

For more on keeping a cat healthy over the long term, read our guides on preventative care for Ragdolls and managing a Russian Blue's weight.

Frequently asked questions

How often is too often for a cat to throw up?

Cornell advises a vet visit if a cat vomits more than once a week, or gags and vomits frequently, especially soon after eating. A hairball every week or two is considered normal.

My cat vomited once but seems fine. Should I worry?

PDSA suggests monitoring an otherwise well cat at home: feed normally, provide fresh water, and watch closely. Contact your vet if your cat seems unwell, vomits again, or shows any other symptom.

Is blood in cat vomit an emergency?

Both Cornell and PDSA list blood in the vomit as a reason to see a vet. PDSA also lists black dots in the vomit. Do not wait to see whether it happens again.

Can I make my cat vomit if she ate something toxic?

No. International Cat Care says not to try to make a cat vomit after eating a poisonous plant. Call your vet immediately and keep the plant label, the time of ingestion, and any symptoms in mind.

Can a diet change cause vomiting?

Yes. A sudden change of diet is listed by PDSA as a common cause, and International Cat Care recommends switching gradually to prevent digestive upset.

Why is my older cat vomiting?

Older cats are more likely to have illnesses such as hyperthyroidism, kidney disease, or diabetes, all of which can include vomiting. Do not assume it is a hairball: have a senior cat that vomits checked by a vet.

Quick checklist

  • One-off vomit, normal energy and appetite: watch, keep water available.
  • Hairball every week or two: normal. Brush more often, especially long-haired cats.
  • Repeated vomiting, lethargy, blood, diarrhea, or more than 24 hours: call your vet.
  • Retching without producing anything, or a possible swallowed object or poison: call your vet or an emergency clinic now.

Keep reading

Sources

Further reading

Reminder: Kittyslovers (The Best Kitty Corner) is an independent blog. Our authors are not veterinarians and this article has not been reviewed by a veterinary professional. Always consult a licensed veterinarian about your cat's health, diet, supplements and medication. Found an error? Let us know.