Constipation in cats


  • Constipation (difficulty passing poo) is a relatively common problem in cats, especially as they get older, or if they have an underlying health problem.
  • There are several causes of constipation in cats ranging from mild to severe.
  • If you suspect your cat is having trouble pooing it’s important to contact your vet for advice straight away.
  • Constipation is a very uncomfortable condition, and left untreated it can become very serious.

Symptoms of constipation in cats

Signs of constipation in cats include:

  • Meowing while pooing — this indicates that pooing is painful.
  • Straining to poo for longer than usual without passing much.
  • Trying to poo several times in a row – you may notice them repeatedly coming in and out of their litter tray.
  • Passing very hard and/or small bits of poo.
  • Passing very small amount of liquid poo (sometimes a small amount of liquid poo can get past the solid constipated poo).
  • Blood in poo or around their bottom.
  • Over-grooming their bottom and back end.
  • A painful abdomen (tummy) - they might look hunched, or growl when you touch them.
  • Lethargy (low energy).
  • Vomiting.
  • Eating less than usual.

Causes of constipation in cats

There are many different things that can cause constipation in cats, including:


If it hurts your cat to pass faeces or get into the right position to poo, they may avoid going and become constipated. This could be because of a problem around their bottom, an injury, or arthritis in their legs, spine or hips.  

A blockage in the guts

Your cat will struggle to poo if something is stopping poo from moving through their guts, such as:

  • Something swallowed that won’t pass through their intestines, such as a bone, toy, or hairball.
  • A tumour.
  • A rectal prolapse (where the inside part of the anus comes outside) - this can also happen as a result of straining.
  • Matted fur around the anus (bottom).


This is a condition that causes the colon (the last section of the guts) to become big and floppy. As a result, instead of moving through the colon, towards the anus, poo builds-up inside it causing constipation. In most cats, the cause of megacolon is unknown, which vets call ‘idiopathic megacolon’.


Dehydration can make poo very solid and difficult to pass. Dehydration can be caused by:

  • Not drinking enough water – most common in cats that only eat dry food and/or don’t have constant access to water.


Stress can cause constipation in cats. Stress can be triggered by a number of things, for example household stress (arguments, noise), not having enough litter trays, a new pet or person in the family, or a new cat in the area. Learn more about stress in cats.

Bad weather

Cats who usually go outside might be put off pooing if the weather is bad.

Litter tray issues

If something is preventing your cat using their litter tray, they may avoid pooing, which can lead to constipation. This could be because their tray is dirty, they don’t like the litter, it’s in a noisy area of the house, or if there simply aren’t enough litter trays for the number of cats in your house (you should have one per cat, plus one spare).


How will my vet diagnose constipation?

Your vet will ask you some questions, and may suggest some of the following:

  • An examination – it may be possible to feel a build-up of poo by feeling your cat’s tummy.
  • A rectal exam (feeling inside their bottom) – in some circumstances this needs to be done under sedation.

If necessary, further investigations such as blood tests, urine tests, X-rays, and an ultrasound scan.

Cat constipation treatment

The exact treatment your cat needs will depend on how constipated they are, and why they became constipated in the first place.

If your cat has mild constipation, your vet might prescribe them a laxative and recommend some changes to their diet. They may also talk to you about encouraging them to drink more, and discuss any helpful changes you could make to their litter tray set up. If necessary, they may also administer a small enema directly into your cat’s rectum (bottom) to loosen their poo and help it pass.

If your cat is dehydrated, they may needto rehydrate them before they are able to pass any poo.

If your cat is severely constipated, they might need an anaesthetic to have the poo removed.

Whether or not your cat needs ongoing treatment will depend on the cause of their constipation.

When to contact your vet

You should always contact your vet if your cat is showing signs of constipation. it can be caused by many different conditions ranging from minor to serious, and can get much worse if it’s left – so it’s always better to be safe than sorry.

You know your cat best. Always contact your vet if you’re concerned.


How do I help a constipated cat?

If your cat is otherwise healthy, you can help them stay regular by making sure:

  • They drink lots of water
  • They move around regularly
  • They maintain a healthy weight
  • Their litter trays are kept clean and away from noisy areas
  • They are fed a suitable diet
  • They have enough litter trays - you should have at least one tray per cat plus one extra, they should all be in different areas of your house.

Laxatives are available for cats but you should only use them under advice from your vet.

How often should my cat poo?

Most cats poo between one and three times a day (more often for kittens). However, every cat is different, so contact your vet if your cat’s pooing habits have changed, or if you’re concerned.

How can I tell if my cat is struggling to wee or poo?

It can be difficult to tell the difference between a cat struggling to wee and struggling to poo, especially if you have a female cat. Sometimes the position of their tail can help — it’s often held up when trying to poo but held down when trying to wee.

How can I prevent my cat from becoming constipated?

Ensure your cat has access to a clean litter tray or the outside, and to avoid competition with other cats in the household you will need one tray per cat plus one extra. If your cat has long hair – brush it regularly to prevent matted fur forming around their bottom.

Encourage your cat to exercise regularly as being overweight or obese can predispose cats to constipation. Ensure your cat has access to clean, fresh water; some cats prefer to drink from running water so a water fountain may be preferable.

Published: January 2024

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Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.