Constipation in cats

Constipation in cats is when they have trouble passing poo which is hard or dry. This is a common problem in older cats. It’s not usually dangerous in the short term but can become life-threatening if untreated. 

Constipation in older cats may not have a specific cause. It can lead to permanent damage to the bowel, a condition called megacolon. Other common causes of constipation include injuries to the pelvis, loss of nerve control (spinal cord disease) and masses in the colon or anus. It is very important to be aware that straining to pee looks very similar in cats, and this is much more urgent. Call a vet if your cat is straining and you’re unsure why.


What to do

What to do if  your cat is constipated

If your cat is constantly going in and out of their tray or showing signs of discomfort, contact a vet straight away. 

If you think your cat 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 cat is producing is noticeably less than usual, a vet check is recommended. 

Painful or difficult pooing should also be checked, even if the amount seems normal.

How to tell if your cat is constipated

  • Spending a lot of time in the pooing position
  • Visibly straining or having abdominal contractions
  • Crying or calling, especially in their tray or favourite toileting spot
  • Passing only very small amounts of poo or none at all 
  • Stools (poo) are dry and hard, possibly with a small amount of mucus 
  • Vomiting, eating less or becoming quiet and subdued.

Cats may not pass stools for a day or two after a bad bout of diarrhoea. This can be normal as long as there is no straining or discomfort.



Why is my cat constipated?

Common  causes of constipation in cats

In many cats, the gut movement slows down with age. This can lead to build-up of faeces. The end of the intestine becomes dilated, which worsens the problem. This can progress to Megacolon.

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

Lack of exercise, obesity or unbalanced diets.

Eating too much of things that are hard to digest, like hair or bones. For example, due to overgrooming or hunting.

Arthritis or other painful conditions that make straining or positioning to poo difficult. 

Stress. Some cats can become constipated if they’ve been too stressed to use the litter tray for several days, or if something is putting them off using it.

Rare conditions affecting nerve and muscle function. 

Rare causes of constipation in cats

Dysautonomia or other forms of neuromuscular (nerve and muscle) disease 

Birth defects

Spinal cord disease

Rectal diverticula (deformity on the rectal wall)

Other illnesses, such as hypothyroidism, hypokalemia or hypocalcemia

When to worry

When to worry about constipation

Contact a vet straight away if your cat is repeatedly straining without producing anything, especially if they are also vomiting or not eating.


How to prevent constipation in cats

Constipation due to medical problems usually requires specific medications to prevent repeated episodes.  

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. 

Good water intake can help prevent constipation. This can be encouraged by changing the water in the bowl frequently or providing a cat fountain.


Diagnosing constipation in cats

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

Home treatment

 How can I help my cat 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 cat to drink water and, if there is no vomiting, feed wet food or add water to the food.

If constipation is due to excessive ingestion of hair, a hairball paste may be able to help. This is best discussed with a vet.

Vet treatment

What is the treatment for constipation in cats?

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

If your cat 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 rectally (given directly into your cat’s bottom) and are not safe to give by mouth.
  • Osmotic laxatives draw water into the stool to make it softer. These are not safe if your cat is dehydrated.
  • 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 which is 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 are especially useful in cases where the gut is not moving properly, like Megacolon. They can be dangerous if an obstruction is present.

Serious cases of constipation require enemas 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.


Are some cats more at risk of constipation than others?

Older cats are at higher risk of constipation, especially if they’ve had it before. 

Cats that have previously suffered pelvic injuries may also be at higher risk

Manx cats are at risk for several conditions that can cause constipation

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