Why Is My Cat Throwing Up? Common Causes Explained

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By Dr. Lila Brooks | Health & Wellness Column | The Pet Standard

It can be alarming to hear that telltale retching sound from another room and then discover your cat has been sick again.

Occasional vomiting in cats can be perfectly normal, but when it becomes frequent or severe, it’s natural to feel concerned.

In this article, we’ll explore the common reasons cats vomit, when you should worry, and what you can do to help your feline friend feel better. From hairballs to allergies, parasites to underlying disease, we’ll walk through it all calmly and clearly so you know when to monitor and when to seek help.

Occasional Vomiting: What’s Normal?

Before panicking, it’s important to recognise that occasional vomiting isn’t always a sign of serious illness. Cats may vomit from time to time due to:

• Eating too quickly

• A minor dietary upset

• Hairballs (especially in long-haired breeds)

• Grass eating

If your cat vomits once every few weeks, is otherwise healthy, and has a good appetite, it’s probably not a cause for concern. But if vomiting becomes frequent (more than once a week), is accompanied by lethargy or diarrhoea, or you notice blood, it’s time to look deeper.

Common Causes of Vomiting in Cats

1. Hairballs

Hairballs are one of the most common culprits. As cats groom themselves, they ingest loose fur, which can accumulate in the stomach. Occasionally, this forms a hairball that your cat expels by vomiting.

Signs: Gagging, retching, or producing a cylindrical mass of fur.

Solution:

• Brush your cat regularly to reduce loose hair — brushes start at around £8–£15.

• Use a hairball control gel like Katalax (approx. £12–£15 per tube).

• Switch to a hairball-control diet like Hill’s Science Plan Hairball Indoor (£25–£35 for a 2kg bag).

If hairballs are very frequent, speak to your vet, as it may signal gastrointestinal issues or excessive grooming due to stress.

2. Eating Too Quickly

Some cats are “speed eaters” and may regurgitate undigested food shortly after meals.

Signs: Vomiting food soon after eating, without much retching or effort.

Solution:

• Try slow feeder bowls (from £10–£20)

• Feed smaller, more frequent meals throughout the day

• Consider puzzle feeders to make eating a mental activity

3. Dietary Sensitivity or Food Allergies

Cats, like humans, can develop sensitivities to certain proteins or additives in their food. Vomiting may be triggered by a reaction to ingredients in their regular diet.

Signs: Vomiting after meals, itchy skin, diarrhoea, or poor coat condition.

Solution:

• Switch to a hypoallergenic or limited-ingredient food like Royal Canin Hypoallergenic (£30–£40 for 2kg)

• Always make diet changes gradually over 7–10 days

• Consult your vet to rule out other causes

4. Gastrointestinal Parasites

Worms and other parasites can irritate the digestive system, leading to vomiting and other symptoms like weight loss or bloating.

Signs: Vomiting, change in appetite, pot-bellied appearance, or worms visible in vomit or stool.

Solution:

• Routine worming every 3 months using products like Milbemax or Drontal (£5–£10 per tablet, depending on weight)

• Vet check for faecal analysis if symptoms persist

5. Toxins or Foreign Objects

Curious cats may ingest something they shouldn’t from houseplants and string to cleaning products.

Signs: Sudden, violent vomiting, drooling, tremors, or lethargy.

What to do:

• Contact your vet immediately

• Poisoning or obstruction is a medical emergency

• Emergency vet visits can cost £100–£250, with additional fees for diagnostics or surgery

6. Chronic Illnesses

If vomiting is persistent, especially in older cats, it may be a sign of chronic conditions such as:

• Chronic kidney disease

• Hyperthyroidism

• Inflammatory bowel disease

• Cancer

Signs: Frequent vomiting, weight loss, appetite changes, or increased thirst.

What to do:

• Book a consultation with your vet (£40–£60 average)

• Blood tests may be needed (£70–£150)

• Early diagnosis can significantly improve outcomes

When to See the Vet

You should contact your vet if your cat:

• Vomits more than once in 24 hours

• Vomits regularly (more than once a week)

• Is lethargic or hiding

• Has blood in vomit

• Has diarrhoea or a swollen abdomen

• Shows signs of dehydration or weight loss

A single episode of vomiting may not be urgent, but always trust your instincts. If something feels off, it’s worth checking.

How Vets Diagnose the Cause

Your vet may recommend:

• A full physical examination

• Bloodwork to check organ function

• Ultrasound or X-rays

• Faecal testing for parasites

• An elimination diet trial

Treatment costs will vary depending on the diagnosis but expect to pay £100–£300 for initial testing in more complex cases.

Preventing Vomiting in Cats

While not all vomiting is preventable, here are some ways to reduce the risk:

• Feed high-quality, easily digestible food

• Groom long-haired cats regularly

• Use slow feeders to prevent gorging

• Keep toxic plants and foods (like lilies, chocolate, or onions) well out of reach

• Worm your cat regularly and keep up with annual vet checks

Final Thoughts

A vomiting cat can be worrying, but in many cases, it’s manageable with a few adjustments and the right care. Whether it’s hairballs, eating too fast, or a more serious condition, staying observant and informed will help you make the best decisions for your feline’s health.

If your cat is throwing up regularly or seems unwell, don't delay a prompt trip to the vet can make all the difference. With early detection and a calm, practical approach, your cat can get back to feeling their very best.