Dog constipation: What to do if my dog can't poo

Constipation is a common problem in dogs. It happens when poo builds up in the colon instead of passing out normally, which makes it hard, dry and difficult to move. A dog with constipation will often strain to go to the toilet but produce very little, or nothing at all.

Watching your dog struggle to go to the toilet can be worrying, especially if you are not sure how serious it is. Below, our expert explains what causes constipation in dogs, how to help a constipated dog at home, and when it is time to contact your vet.

How long can a dog go without pooing?

Most dogs poo between one and three times a day, though this varies from dog to dog. If your dog has not pooed for more than two to three days, or is straining without producing anything, contact your vet. Constipation tends to get worse the longer it is left, so it is better to seek advice sooner rather than later.

Signs your dog may be constipated

Signs that a dog is constipated include: 

• Straining to poo for longer than usual, often without producing much
• Whining or whimpering while trying to go to the toilet
• Trying to poo several times in a row
• Small amounts of liquid poo, as this is often all that can pass a blockage
• Blood in the poo, or spotting blood from their bottom
• A painful, tense abdomen
• Low energy, vomiting, or going off their food

If your dog is showing any of these signs alongside vomiting or a swollen, painful tummy, contact your vet promptly, as this can point to a more serious blockage.

What causes constipation in dogs?

Constipation has several possible causes. Anything that blocks or puts pressure on the gut can stop poo passing normally. Examples include eating bones or foreign objects, an enlarged prostate in male dogs, being overweight, or matted fur around the anus. 

Pain can also cause constipation, because it makes it difficult for a dog to get into position to go to the toilet. This is often seen in dogs with arthritis or hip problems. Dehydration and conditions that slow the gut down, such as an underactive thyroid, can make poo harder and more difficult to pass. 

What to give a constipated dog

If your dog is otherwise well, there are a few things you can try at home to help relieve mild constipation. Keep them moving with regular walks, as exercise can help stimulate the gut. Make sure they always have access to fresh water, and check their diet contains an appropriate level of fibre for their size and breed.

Do not give your dog a laxative, stool softener or any other remedy without speaking to your vet first, as some options are unsafe depending on the cause of the constipation. Never attempt to give your dog an enema at home, as this should only ever be carried out by a vet. For more general advice, take a look at how often should I bathe my dog and other everyday health tips. 

How vets treat constipation in dogs

Your vet will examine your dog and ask about their toileting habits. They may also run blood tests, take an X-ray, or perform an ultrasound scan to find the underlying cause.

Mild constipation is often treated with a prescribed laxative alongside changes to diet and water intake. Your vet may also give a small enema to help loosen and pass the poo. Dogs with more severe constipation sometimes need an anaesthetic so the poo can be removed safely. Ongoing treatment depends on what is causing the constipation, so your vet will tailor this to your dog.

When to contact your vet

Always contact your vet if your dog is showing signs of constipation. The cause can range from mild to serious, so it is best to have them checked rather than wait and see. Seek help sooner if your dog also seems distressed, has a swollen or painful tummy, or is vomiting.