Constipation in Cats

How to keep things 'moving' for your kitty


This article is written by Pet Circle's qualified veterinarian, Dr Carla Paszkowski, BVSc (Hons)

You might be surprised to hear that constipation is a common problem for our feline friends. Constipation is defined as the inability to easily or routinely evacuate the bowels. It can affect many cats, particularly as they age. It is an extremely frustrating issue to deal with - both for your kitty and for you!

In some cases, cats can suffer from colonic obstruction and become completely unable to evacuate their bowels. If left untreated, this can lead to stretching of the bowels in a condition known as megacolon.

So, it's very important to stay on top of the problem and seek veterinary attention if you suspect your cat is constipated.


1. Causes of Constipation

2. Diagnosis of Constipation

3. Treatment of Constipation

4. The Best Diets for Constipation

Causes of constipation in cats

1. Dehydration - this is the most common contributor. Dehydration can be caused by decreased water intake if your cat isn't drinking enough water, or increased water loss such as from kidney disease, vomiting, diarrhoea, or medication causing increased urination.

2. Hairballs - common in long-haired cats. While many hairballs are regurgitated, or 'coughed up', some hairballs may pass through the intestines and cause an uncomfortable blockage in the colon. Read more about how to manage Hairballs in Cats.

3. Ingestion of foreign bodies - if your cat may have ingested something they shouldn't have, it could cause constipation. This is a medical emergency.

4. Orthopaedic issues such as arthritis or pelvic injuries - if your kitty finds it painful to assume the 'pooping position', they may be holding on for longer than they should. This can lead to dehydrated stools that become difficult to pass.

5. Neurologic disorders - If there is a problem with the nerves connecting to the smooth muscle of the colon, the colon can become limp and create a megacolon. This can occur with a spinal cord injury, for instance during a car accident, or in an animal with intervertebral disc disease (IVDD - commonly seen in Dachshunds). Certain medications, such as opioids, can also cause the nerves or smooth muscle to become inactive.

6. Genetic problems - for example, Manx cats can suffer from congenital spinal cord deformities.

7. Medications - some drugs can slow the motility of the gastrointestinal tract. These include opioids, anticholinergics, or sucralfate

8. Stress or behavioural reasons - such as a change in environment, a new animal in the household, or any problems with the litter box

9. Megacolon - this is a condition where the colon dilates, enlarges, and becomes immotile. It may be secondary to chronic dry faecal bulk, or it may have no known cause. Read more about Megacolon in Cats.

10. Tumours of the intestinal tract, colon, anal glands, or associated area.

How is Constipation Diagnosed?

Your vet will be able to diagnose constipation fairly easily with an abdominal palpation, rectal exam, and usually xrays. Xrays will allow your vet to observe the extent of bulky faecal impaction, and whether any distension or gas buildup is present. Xrays can also help rule out urinary obstruction.

Your kitty may also require blood and urine tests to investigate other issues such as urinary or kidney disease. If a tumour or other soft tissue abnormality is suspected, an ultrasound may be required.

How to Treat Constipation in Cats

In the short term:

In cases of mild acute constipation, your cat may respond to a warm water enema or a liquid rectal medication without anaesthesia. However, in cases of severe constipation or megacolon, your cat may require a full enema under general anaesthesia. Either of these will need to be performed at your veterinary clinic.

In the long term:

There are plenty of changes you can make at home to prevent the recurrence of constipation. These include:

1. Increase hydration

To keep your cat hydrated, you can try swapping over to a wet cat food diet, add some water to the food, or encourage water intake with a water fountain. Cats are naturally drawn to fresh, moving water, so a water fountain is usually very effective. Our top recommendations include:

2. Change their diet

If your pet is generally very prone to constipation or is undergoing medical management of megacolon, your vet may recommend either a low-residue diet or a high fibre diet. The two are generally opposites - low residue diets are low in fibre and therefore create smaller stools that are easy to pass, whereas high fibre diets create bulky stools that encourage motility.

Often the ideal diet plan involves feeding a low residue diet until the immediate constipation is alleviated, and then introducing more fibre to prevent a future episode. Ultimately, the ideal diet for your pet will depend on the cause of the constipation and the current situation, so always consult with your vet before administering a new diet.

Low-residue diets

A low residue diet helps reduce faecal bulk and creates smaller stools. Low residue diets should be easy to digest - this means they are high in digestible protein, low in fat, and low in fibre - although not without fibre altogether. Some fibre is needed to feed the 'healthy bacteria' in the colon, which can help prevent megacolon from developing. Most low residue diets contain a specific blend of high quality fibre in low quantities to help maintain this balance. See section below for the top low residue diets for cats and dogs.

High fibre diets

On the other side of the coin, high fibre diets create a bulkier stool. Just as humans take psyllium husk or Metamucil to 'stay regular', a high fibre diet can help keep things moving for pets too. Instead, a high fibre diet may be better indicated long term, after the acute constipation episode has passed. See section below for the top high fibre diets for cats and dogs.

Which cat foods are high in fibre? While most brands don't tend to display fibre content as a primary callout, you will generally find that most feline weight control or hairball control cat food diets are high fibre. Our top recommendations include:

3. Add fibre to the food.

You can add some extra fibre to your cat's diet by mixing in some cooked, mushy pumpkin or zucchini with their regular cat food. You can also sprinkle some natural psyllium husk onto the food; however always ensure you select a natural psyllium product free from any artificial sweeteners such as Crooked Lane Harvest Psyllium made specifically for pets. Try starting with half a teaspoon once daily, and adjust the dose based on your cat's response.

4. Try a stool softening product

In some chronic cases where hydration alone just doesn't cut it, you might need to keep a stoll softening product or a laxative on hand. These usually come in the form of a tasty paste which can be fed directly or added straight onto the food. These are not suitable for kittens; only adult cats.

What are the best laxatives for cats? If your cat's constipation is sudden, your vet may recommend lactulose, which works by osmotically increasing fluid production in the lumen of the intestine.

However, for ongoing management most veterinarias recommend a paraffin-based product. Paraffin is an oil which coats the faeces and helps provide lubrication to prevent hard, dry faeces from 'getting stuck'. Unlike lactulose, paraffin doesn't draw fluid from the body into in the intestines, so it won't depelete your cat of water and electrolytes. However, prolonged use of paraffin can prevent the nutrients in your cat's food from being absorbed, so we only recommend using occasionally.

Products that contain paraffin as the active ingredient include Aristopet Paste, Hartz Hairball Remedy, and Troy Laxapet Gel.

Our top laxatives for cats include:

Aristopet Cat Laxative Paste

This paste contains soft white paraffin and has a malt flavour that most cats accept readily. It is great to keep on hand for cats who suffer from occasional constipation.

Hartz Hairball Remedy Plus Paste

Designed for hairballs, this paste is also helpful for constipation. It is salmon-flavoured and enriched with omega fatty acids and vitamin E for a healthy skin and a shiny coat

Troy Laxapet Gel

Laxapet Gel is suitable for use in constipation or hairballs. With paraffin as the active ingredient, this product is safe and a great option to keep things moving.

5. Change the litter type or cleaning routine

Cats are innately very clean animals, and may refuse to use their litter box if they don't like the litter or it's not being cleaned regularly enough.

If you suspect that your kitty is displeased with their litter box, it can help to offer an extra litter tray, a couple of different types of litters, or more frequent cleaning regime.

Don't like cleaning the litter box twice a day? Why not try an automatic self-cleaning litter tray? Or perhaps a simple change over to a clumping litter? When mixed with urine, clumping litter binds together and forms a solid clump. This allows you to remove all the soiled bits easily, leaving only clean litter behind. Because of this, one litter tray can last up to two weeks and hardly smells at all. As a cat owner who has tried almost every type of litter, my top recommendation is without a doubt Rufus and Coco Wee Kitty Corn Litter.

6. Keep their weight down

Obese and overweight cats are far more likely to suffer from constipation. The best ways to keep your cat's weight down involves, just as with humans, exercise and diet.

To exercise your cat, try to figure out what type of toy they like best. Some people assume their overweight cat is too lazy to play with toys, but then discover that their cat just needed a more interactive toy, or a different type of toy such as one containing feathers.

Address The Underlying Problem

While the above remedies can help relieve constipation as a symptom, you will need to address the underlying cause to seek a proper solution. Your vet will be able to investigate and address issues such as kidney disease, arthritis pain, hyperthyroidism, or neurological abnormalities.

Take-Home Message

Consipation in cats can be a frustrating issue to deal with, but there are plenty of ways to remedy the situation at home. By taking some time to address the underlying causes, you can help to prevent them from recurring and keep everyone happy!

Further Reading

Check out our other vet-written articles below, or take a look at our Vet Tips Page for many more topics and guides!

Are Hairballs Dangerous?

Megacolon in Cats

Kidney Disease in Cats

Urinary Crystals in Pets

Why Do Some Cats Pee Where They Shouldn't?

Which is the Best Cat Litter?