Why is my cat throwing up? Causes and when to call the vet
That sound at 3 a.m. Every cat owner knows it. Most of the time it's a hairball, but sometimes vomiting is the first sign of something that needs a vet. Here is how to tell the difference.
Written by
- Amelia Brown · Staff writer
FYI Summary
Here’s what matters
If two or more of these apply today, call your vet.
- Cats vomit for many reasons, including hairballs, diet, parasites, infections, swallowed objects and diseases of the kidneys, liver or pancreas.
- Vomiting is forceful, while regurgitation is passive and usually brings up undigested food without heaving.
- See your vet if your cat vomits more than once or twice in a day, according to the Merck Veterinary Manual.
- Vomiting with blood, belly pain, depression, dehydration, weakness, fever or weight loss also needs a vet.
- Frequent hairballs are worth a vet visit too, because they can irritate the stomach or block the digestive tract.
Cats have a talent for throwing up on the one rug that cannot go in the washing machine.
Usually it happens once, your cat walks off looking unbothered, and that is the end of it. But vomiting is also one of the first signs of problems that cannot wait, and cats are good at hiding the rest.
Here is what usually causes it, how to tell vomiting from regurgitation, and the signs that mean it is time to call the vet, based on the Merck Veterinary Manual.
Why is my cat throwing up?
Common causes include hairballs, food allergies, parasites, infections and swallowed objects; vomiting can also come from digestive disease, kidney or liver failure, pancreatitis or tumors.
- Hairballs: swallowed hair from grooming forms lumps that can irritate the stomach or even block the digestive tract.
- Food: food allergies or intolerance can cause vomiting.
- Swallowed objects: anything that is not food, which is why a missing toy part is worth mentioning to your vet.
- Parasites and infections: both can upset the digestive system.
- Disease: digestive disease, kidney or liver failure, pancreatitis and tumors can all show up as vomiting.
Is my cat vomiting or regurgitating?
Vomiting is active, with heaving from the belly; regurgitation is passive and usually brings up undigested food, often in a tube shape, with no heaving.
The difference matters because the two point to different parts of the body. If you can, take a short video or a photo of what came up; it helps your vet more than a description.
When should I take my cat to the vet for vomiting?
The Merck Veterinary Manual says to see your vet if your cat vomits more than once or twice in a day, or if the vomiting comes with other signs of illness.
- Frequency: more than once or twice in a day.
- Blood: in the vomit.
- Other signs: belly pain, depression, dehydration, weakness, fever or weight loss.
- Hairballs: frequent episodes, not just the occasional one.
Long-term vomiting needs a proper diagnosis, which can mean blood tests, imaging and sometimes endoscopy. Those bills add up, which is where our cat insurance comparison comes in.
Are hairballs normal in cats?
An occasional hairball is common in cats, but frequent hairballs are a reason to see your vet, according to the Merck Veterinary Manual.
Hair forms lumps in the stomach as your cat grooms. Ask your vet about brushing and hairball management, especially for long-haired cats.
What can I do at home for a vomiting cat?
For a single episode in a cat that otherwise seems normal, watch closely and call your vet before changing food or giving anything.
Merck notes that vets sometimes advise resting the digestive system for brief vomiting of less than one to two days with no other signs, while keeping water available. That decision belongs to your vet, who knows your cat; never give human medicine.
What to note before you call the vet
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Recently switched foods? Our guide to wet vs dry cat food covers what to look for on the label.
Frequently Asked Questions
Why does my cat throw up undigested food?
Often it is regurgitation rather than vomiting: food comes back up without heaving, often undigested. Tell your vet which one you saw, because the causes differ.
Is it normal for a cat to throw up once a week?
It is worth asking your vet. Merck lists frequent hairball episodes and long-term vomiting as reasons for a check-up, even when your cat seems fine otherwise.
When is cat vomiting an emergency?
When it happens more than once or twice in a day or comes with blood, belly pain, depression, dehydration, weakness, fever or weight loss. Call your vet the same day.
Bottom line
One hairball and a normal cat afterward is usually just a cat being a cat. More than once or twice a day, blood, or any other sign of illness means a call to your vet today.
Sources
(1)
- Vomiting in Cats (Craig B. Webb, PhD, DVM, DACVIM; last updated September 2024)(opens in a new tab) — MSD Veterinary Manual (known as the Merck Veterinary Manual in the US and Canada) (accessed )
Information, not veterinary advice.