Dog constipation


  • Constipation is when your dog is struggling to poo but very little or nothing is coming out.
  • Several things might cause constipation in dogs, which can range from mild to serious.
  • Always contact your vet if your dog is struggling to poo, as the cause may need to be investigated and treated.

General information

If your dog is constipated they will be trying to poo but only producing a small amount. When poo sits in the colon (the last part of the intestines) instead of being passed out, all the water from it gets absorbed, so it can get very hard. You might also see small amounts of liquid poo, as this is all that can get past a blockage. Some dogs may not be able to poo at all (this is called obstipation).

Signs that your dog is constipated include:

  • Whining or whimpering while pooing — this indicates that pooing is painful
  • Straining to poo for longer than usual — you might also see your dog straining if they have diarrhoea, but with constipation they won’t produce very much
  • Trying to poo several times in a row
  • Blood in poo or spotting blood from their bottom
  • Over-grooming their back end
  • Ribbon-like poo
  • Mucus on the poo

Your dog may also have a painful abdomen (tummy), lethargy (low energy), vomiting, and/or be off their food.

Causes of constipation in dogs

There are many potential causes of constipation, including:

Blockages — Anything that puts pressure on or gets in the way of the intestines, colon or anus (back passage) can lead to constipation because it stops the normal passage of poo. This can include:

  • A gut blockage or blockage in the anus (back passage)
  • Eating bones or sharp objects, which can get stuck in the gut and/or be very painful to pass
  • Cancer in the intestines or abdomen (tummy)
  • Enlarged prostate or prostate cancer in male dogs
  • Being very overweight
  • Rectal prolapse (where the inside part of the anus comes outside) — this can also happen as a result of too much straining to poo
  • Matted fur around the anus can block poo from coming out

Pain — sometimes if it is very painful to poo, this can cause constipation because it makes it hard for your dog to get into the correct posture to go.  Pain that might cause constipation includes:

Other causes — anything that causes dehydration or slows down the gut can cause constipation as it makes the poo hard and difficult to pass. Examples include:

How will my vet diagnose constipation?

Your vet will examine your dog, this might include a rectal exam which is sometimes better to do under a sedative. They will ask you lots of questions about your dog and their pooing habits. Further tests will depend on what the likely cause of the constipation is but might include blood tests, testing your dog’s poo, X-rays and/or ultrasound scans.

Check out our advice on how to collect a poo sample from your dog.


If your dog has mild constipation, your vet might prescribe a laxative and recommend changes to their diet and water intake. Your vet may also administer a small enema directly into the rectum (back passage), which should loosen any poo in the colon and help it to pass.

Dogs with more severe constipation might need an anaesthetic to have the poo removed with a larger enema of warm water.

Further treatment will depend on the cause and severity of the constipation.

When to contact your vet

You should contact your vet if your dog is showing signs of constipation. Constipation can be caused by many different conditions ranging from minor to serious, so it’s always better to be safe than sorry. Constipation can get worse the longer you leave it so it’s always better to see a vet as soon as possible.

You know your dog best, always contact your vet if you’re concerned.


How do I help a constipated dog?

If your dog is otherwise healthy you can help them poo by keeping up exercise (which can help pooing), making sure they drink lots of water, maintain a good weight, and have a suitable diet.

Laxatives are available for dogs, you should only use them under advice from your vet as the cause of the constipation may need to be investigated and treated.

How often should my dog poo?

Generally dogs poo between one and three times per day with puppies pooing a bit more often. Every dog is different so contact your vet if your dog’s pooing habits have changed or if you’re concerned.

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

It can be difficult to tell the difference between a dog struggling to wee and struggling to poo, especially in female dogs. Sometimes the position of their tail can help — it is often held up when trying to poo but held down when trying to wee.

Published: June 2023

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