Constipation in dogs

Constipation is when dogs have trouble passing poo and this is hard or dry. This is a common problem after they eat bones or hard-to-digest foods. It can be urgent if severe and become life-threatening if left untreated.

Non-food materials can also cause constipation if they make it to the colon but are difficult to pass. Other possible causes are tumours at the end of the intestines or anus, a broken pelvis or spinal cord disease. It is common for dogs to strain when they have pain in their anal sacs or perineal fistulas and this can be confused with constipation.

What to do

What to do if your dog is constipated

If your dog is constantly trying to poo or showing signs of discomfort, a vet check is recommended.

If you think your dog hasn’t pooed for 48 hours, a vet assessment is recommended. This can be more urgent if they are off their food or vomiting.

If the amount of poo your dog is producing is noticeably less than before, a vet check is recommended.

How to tell if your dog is constipated

Spending a lot of time in the position to poo.
Visible straining or abdominal contractions.
Crying or whimpering while trying to poo.
A very small amount or no faeces passed.
Stools are dry and hard, a small amount of mucus may be present.
Can have vomiting, appetite loss or lethargy at the same time.

Dogs may take a day or two to start passing faeces again after a bad bout of diarrhoea, this can be normal as long as there is no straining or discomfort.

Causes

Why is my dog constipated?

Common causes of constipation in dogs

Eating food that is very hard to digest, such as bones.

Prostatic disease in male dogs.

Injuries to the bones of the pelvis can reduce the space available for poo to pass through, which can lead to serious constipation. This can become noticeable some time after a serious accident or injury.

Lack of exercise, obesity or unbalanced diets.

Arthritis or other painful conditions that make straining or positioning for pooing difficult.

Conditions that cause muscle weakness or nerve problems.

Other causes of constipation in dogs

Dysautonomia or other forms of neuromuscular disease

Congenital malformations

Spinal cord disease

Rectal diverticula (pockets that form in the rectal wall)

Metabolic problems such as hypothyroidism, hypokalemia or hypocalcemia.

When to worry

When to worry about constipation in dogs

Contact a vet straight away if your dog also shows any of the following symptoms:

Vomiting
Lack of appetite
Pain
Passing blood

Prevention

Can I prevent constipation in my dog?

The most important thing to prevent constipation is to have a healthy and balanced diet, with the right proportions of the different types of fibre.

Regular walks and other forms of exercise, as well as maintaining a healthy weight, improve gut function.

Diagnosis

How is constipation diagnosed in dogs?

Severe constipation can sometimes be diagnosed on abdominal palpation or rectal examination. This may not be possible in bigger dogs or if they are very uncomfortable. A detailed evaluation of the severity and possible causes of the problem requires x-rays of the abdomen.

Home treatment

How can I help my dog with constipation?

The right treatment for constipation depends on the cause, so getting a diagnosis is always important.

Preventing dehydration and increasing the water content of the stool is often helpful. Encourage your dog to drink water and, if there is no vomiting, feed wet food or add water to the food.

Vet treatment

What is the treatment for constipation in dogs?

Depending on the cause of the constipation, there are several medications or procedures your vet may recommend.

If your dog is dehydrated, it is very important to correct this as quickly as possible.

Mild cases can be treated with laxatives. These come in different types:

Emollient laxatives prevent water from being removed from the stool and make it softer.
Lubricant laxatives coat the stool and make it slippery and easier to pass. These are used directly into your dog’s bottom (rectally) and are not safe to give by mouth.
Osmotic laxatives draw water into the stool to make it softer. These are not safe if there is dehydration.
Stimulant laxatives increase gut movements to push the stool onward. This can be done by increasing bulk (fibre products) or stimulating the intestinal wall directly. These laxatives are not safe if there is a physical blockage making stool passage impossible.
Some laxatives will work in more than one way. Lactulose, for example, is both osmotic and stimulant.

There are medications that directly increase the strength and frequency of intestinal movements, called prokinetics. These can be dangerous if an obstruction is present.

Serious cases of constipation require enemas to be performed under sedation, this is a procedure where fluid and lubricants are administered directly into the rectum and the faeces are gently removed.

Severe cases may require surgery to empty the colon.

Risk