A cat having a veterinary check up after diarrhoea

Why does my cat have diarrhoea? Causes of diarrhoea in cats

We all know how rubbish we feel after a bout of diarrhoea and vomiting – and no one likes to imagine their cat suffering in the same way. Cat poo, poop or faeces – there are lots of names for it, but if your cat is experiencing an episode of runny or continuous diarrhoea, you may need to take action.

While a one-off bout of diarrhoea may simply be a sign that your cat has eaten something that’s unsettled their stomach – adventurous outdoor cats often have a particularly ‘experimental’ diet – there are many possible causes of diarrhoea in cats.

Cat diarrhoea is a good reason to visit your local vet, who will help to establish the cause and recommend treatment, if necessary. Always book an appointment right away if the diarrhoea is chronic or contains blood, or if you suspect your cat has come into contact with a toxic or harmful substance.

Diarrhoea in cats: the warning signs

If your cat has a one-off bout of diarrhoea but is otherwise alert, active, and showing no other symptoms, it’s probably no cause for alarm.

If she is lethargic, has diarrhoea for over 24 hours, is vomiting, loses her appetite, or displays any other symptoms, don’t delay – get her to your local vet, fast. Prolonged diarrhoea can quickly cause your cat to become dehydrated, so it’s important to be vigilant.

Common causes of cat diarrhoea

There are many possible causes of diarrhoea in cats – we’ve listed some of the most common reasons below.

  • Worms
  • Sensitive stomach
  • Changes to their diet
  • Lactose intolerance
  • Stomach infections (gastritis)
  • Serious conditions such as inflammatory bowel disease
  • Ingesting poisonous or harmful substances
  • Causes of diarrhoea in cats

An infestation of worms, such as roundworm or tapeworm, can trigger diarrhoea in your cat. When it comes to worms, prevention is better than cure, and a regular worming routine will help to keep your cat worm free.

If your cat has a particularly sensitive stomach they may be unable to tolerate certain foods, which can lead to diarrhoea. While indoor cats are less at risk than a cat who’s used to hunting, any changes to your cat’s diet can cause stomach upsets.

It’s best to stick to a balanced, healthy diet that your cat is used to – particularly if your cat has an intolerance to certain foods. Your vet will advise you on a suitable diet - there are many specifically formulated foods for for cats with a sensitive stomach.

Stomach infections (gastritis) are a common cause of diarrhoea in cats – and often trigger both sickness and diarrhoea. The right diet (see above) and plenty of water can help clear up the problem in a few days, but always consult your vet if your cat doesn’t recover quickly.

A number of serious conditions can cause diarrhoea and sickness in cats, including inflammatory bowel disease, congestive heart failure, diseases of the central nervous system, cancer, liver and kidney diseases.

Your vet will test your cat to rule out these conditions if necessary, and to establish the best course of treatment to get your cat back in tip-top health.

Ingesting poisonous or harmful substances can give your cat diarrhoea. If you believe your cat has come into contact with a toxic substance, get her to your vet as quickly as possible. Our tips can help you protect your cat from poisonous plants and harmful substances.

Did you know?

After examining your cat, your vet will classify their diarrhoea as either a primary intestinal disease or secondary diarrhoea – the latter meaning the diarrhoea is caused by a more dominant disease.

 “Your vet will advise you on a suitable diet - there are many specifically formulated foods for for cats with a sensitive stomach.”

How do I stop my cat getting diarrhoea?

The short answer is, you can’t – but you may be able to reduce the risk of an upset stomach in your cat.

Your vet can give you advice on the best diet to feed a cat with a sensitive stomach or lactose intolerance, and it’s vital to keep toxic substances well out of reach of your feline friends. See our tips to protect your cat from poisonous plants and harmful substances. 

Need help and advice for a cat with diarrhoea?

If your cat has diarrhoea for over 24 hours, make an appointment to see your local vet right away. To find your nearest recommended vet or pet clinic, use our Find a Vet page.