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What to do if your cat is throwing up

Cat is throwing up
(Image credit: Getty)

It can be a worrying time if your cat is throwing up. They can’t tell us what’s wrong or how they are feeling, so sometimes it’s hard to know what to do for the best. Vomiting is not a very specific symptom and could be due to an array of different health conditions. In this article, we will look at some of the more common causes of vomiting that vets diagnose in cats, the warning signs you should look out for, and what you can do to help your pet get better.

Causes of vomiting in cats

There are many different reasons why your cat is throwing up. Many cats will be sick from time to time with hairballs, eating grass, travel sickness, or just gulping food down a bit too quickly. But more frequent vomiting could be a sign of an underlying condition. Let’s look at some of the most common causes of why your cat might be vomiting.


A high number of worms could cause vomiting in cats, as well as diarrhoea. Routine parasite treatment should prevent this from occurring.

Food intolerance

Some cats can have food intolerances or allergies to certain ingredients, causing upset stomachs. Inflammatory bowel disease can be seen too.


Pancreatitis is a condition whereby the pancreas (a small organ that helps with the digestion of fats), becomes inflamed. This causes abdominal pain, vomiting, diarrhoea, lethargy and lack of appetite. Pancreatitis can vary in severity but is usually treated with a combination of pain killers and intravenous fluids.

Kidney disease

Cats can either suffer from acute or chronic kidney failure, both of which could cause vomiting. Acute kidney failure usually occurs due to sudden damage to the kidneys, from toxins or injury. Chronic kidney failure is commonly seen in elderly cats, where the kidneys become shrunken and scarred through ageing.

Foreign body

If your cat eats something undigestible this could cause a blockage in its digestive tract. Cats may play with and accidentally ingest small toys, hair bands, tinsel and elastic bands by causing serious problems. Surgery may be required to extract these items.


If your cat eats something poisonous it could cause vomiting. Things that could cause vomiting in cats include lilies, antifreeze and chocolate.


A benign overgrowth of the thyroid gland can cause an increase in metabolism, leading to weight loss despite an increased appetite. These cats may also have digestive upset such as vomiting or diarrhoea. Diagnosis is made by blood tests, with a variety of treatment options available.

Medication side-effects

Some medications could cause upset tummies as a negative side-effect. Check with your veterinarian if your cat is vomiting whilst taking prescribed drugs.


Certain cancers or tumours, such as lymphoma, could cause your cat to vomit. You may see other symptoms too like weight loss and diarrhoea.

When should I take my cat to the vet?

Most of the time cats are sick because of a simple case of gastritis (mild tummy upset). However, you should take your cat to the vet if you notice any of the following more serious signs:

  • Vomiting several times 
  • Vomit with blood in it
  • Being off their food
  • Pale gums
  • Changes in thirst and urination
  • If they are lethargic or depressed
  • Other symptoms such as breathing difficulties, wobbliness or seizures

If you have any doubts, it is far better to take your cat to the vet sooner rather than later.

What will help my cat feel better?

If your cat has just been sick once or twice and is otherwise bright with no other symptoms, you may choose to monitor them at home. Make sure they have access to plenty of fresh water and consider feeding them bland, easy to digest food for a few days. Lean cooked chicken (no fatty skin), white fish, and boiled rice are all good choices, but a commercial sensitivity diet is best as it contains all the nutrients they need.

If your cat is unwell and they require veterinary attention, then treatment will depend on the underlying cause of their illness. They may receive an injection to help stop nausea and vomiting, which can help make them feel brighter. Intravenous fluids may be required if your cat has become dehydrated, and they may also need painkillers if they have abdominal discomfort. 

Your vet will be able to advise you on the tests available to help diagnose your cat's condition, but usually, bloodwork and diagnostic imaging (such as x-rays and ultrasound scans) are a good way of screening for conditions like pancreatitis, kidney disease and foreign bodies.


There are many possible reasons why your cat is throwing up. It is best to get them checked out by a vet, particularly if they have eaten something toxic or if they are showing other symptoms of being unwell. Unless the vomiting resolves immediately, it is usually best to get your cat seen sooner rather than later!

Dr Rebecca MacMillan

Dr Rebecca MacMillan is a companion animal vet who has always had a passion for writing and client communication. She works in the South West and loves complex medical cases.