Cat Constipation: Signs, Causes and Treatment

How will I know if my cat is constipated?

It might not always be easy to tell if your cat’s digestive system isn’t working the way it should. Vomiting and diarrhoea can be more obvious, but constipation can be much harder to spot, especially, as we said, if your cat goes outside to urinate and defecate.

The potential signs of a constipated cat:

1. If your cat uses a litter tray, watch for changes in frequency and consistency. If you notice suddenly that you don’t need to empty the tray as much, or if the stools seem different in size or appearance (hard or crumbly), it could be a sign that constipation is developing.
2. Watch for straining or vocalisation. If your cat seems to be crying out or spending ages in the tray without success, then you should see your vet as soon as possible. This could be a sign of constipation that needs addressing, or it could be a sign of a urinary condition, such as an inflamed bladder or blocked urinary tract, which is a medical emergency.
3. Watch for your cat defecating in the wrong place. If your cat is in pain, is missing or avoiding the litter tray, or is reluctant to go outside to poop, they may be constipated.
4. General malaise. Constipation makes cats feel pretty miserable, just like it can for us. Sometimes, the only sign of your cat being constipated is that they seem off. They may seem lethargic and uninterested in play or in socializing. They may also go off their food because they don’t feel well.

Common causes of cat constipation

There are several things that can cause constipation in cats. The major causes of cat constipation are:

• Dehydration
• Swallowing fur
• Obesity and lack of exercise
• Injuries and pain
• Tumours
• Nerve problems
• Underlying diseases
• Foreign objects.

Let’s have a look at these in more detail:

Dehydration

Cats have evolved from ancestors that lived in hot, desert-like places, so they’re very good at conserving the water in their bodies. This means they tend not to drink very much, which can lead to dehydration and drier stools.

This is even more likely to happen in situations like that of a multi-cat household, where one cat might not have equal access to food and water due to a resident bully. To make sure your cat stays hydrated, place several water bowls around the house so that they have water freely available wherever they are. At a minimum, ensure that there is one more water bowl than the number of cats in the home. Lots of cats love to drink flowing water, so cat fountains can also be a great way to keep your cat hydrated.

Feeding your cat wet food, like the ones that come in pouches or tins, can be a great way to ensure they get plenty of fluids. If the cost of wet food is prohibitive, you can also see if your cat will eat dry food that is soaked in warm water prior to feeding. Some cats don’t like this texture, but some really love it.

Swallowing hair

Cats love to groom and spend about 30–40% of their waking time tending to this important job. It’s perfectly normal for cats to swallow hair during the grooming process, and it usually passes through without any issues. However, long-haired cats and cats that are overgrooming due to things like stress might swallow more than is normal. While some cats that ingest a lot of hair might vomit up hairballs, some may become constipated.

Obesity and lack of exercise

Obesity and lack of exercise are important causes of constipation in cats.  Exercise stimulates the bowel to move. In overweight cats, excess fat in the abdomen can compress the bowel and make it more difficult for faeces to pass.

Injuries and pain

Injuries such as pelvic fractures may physically narrow the passage where the large bowel sits, making it difficult for the cat to pass stools. Also, as cats get older and their joints get stiffer and arthritic, they may find that squatting is painful. They might defecate less frequently, allowing the faeces to dry out and become difficult to pass.

Tumours

Some tumours in the bowel area can block stools from passing through, either by pressing up against the bowel from the outside or taking up space inside.

Nerve problems

The contents of the intestines are moved from one end to the other by waves of muscular contractions called peristalsis. It happens automatically, without us ever having to think about it. Some cats get nerve problems that might hinder this. Some breeds of cat, such as the Siamese, are more prone to this. It can cause something called megacolon, where the colon becomes very slack and dilated.

Foreign objects

This is usually more of a problem for dogs that are prone to eating all and sundry, but it can be an issue for cats too. For example, they may have eaten a bird, including the bones, which can become impacted in the rectum. 

Underlying diseases

Some other diseases, such as kidney disease, can cause dehydration, which can lead to constipation. Any disease that causes your cat to feel unwell may make them less likely to make the effort to go to the toilet, allowing the stools to harden.

When to see a vet for cat constipation and how to treat it

Lots of animals, including cats, may occasionally get constipated as a one-off problem, and it may simply pass and go back to normal. The main things to look out for are blood being passed, excessive straining and pain or vocalisation. Also take note if your cat’s constipation doesn’t resolve within 48 hours.

The treatment for your cat’s constipation will depend on the cause. Your vet may simply give them a laxative enema in the consulting room to see if it gets things moving. Sometimes you may be given drugs to stimulate bowel movement and oral laxatives.

If these don’t get things moving, or the constipation recurs, your vet may want to sedate or anaesthetise your cat to image for things like tumours or pelvic issues and do a full enema to see if they can reset to zero. 

In chronic cases, such as megacolon, your vet may recommend a special veterinary food. This may be a high fibre food to help stimulate contractions of your cat’s colon. On the other hand, if your cat has a narrow pelvic passage for any reason or end-stage megacolon where the bowel is so damaged that it can’t move stools out, they may recommend a very low-fibre food to produce the smallest faeces possible.

Can I prevent constipation in my cat? 

Although we have no control over whether our animals develop a nerve condition or any other disease that can cause constipation in cats, there are some things you can do to help prevent it from happening. Some of these tips can be used as home remedies and may help your cat if they are mildly constipated, or else serve as preventive measures.

• Always keep your cat slim and as active as possible. Exercise is a great stimulant for the bowel. Playing, encouraging exercise and giving cats access to the outside are great ways to keep their bowels moving and healthy.
• Food. Talk to your vet about the best food for your individual cat. 
• Keep your cat well-hydrated. Feed them wet food if possible, or see if they will eat dry food soaked in warm water. Have lots of water bowls with fresh, clean water around the house and garden. This way, they never have to go far for a drink. Fountains encourage a lot of cats to drink because they like flowing water.

Hopefully, your cat will sail through life with happy bowels, but if you’re ever concerned there might be a problem, always talk to your vet. They would much rather be on the safe side and catch a problem before it gets too bad. It might be that a simple change of food is needed to give your cat more fibre or more moisture, but if there is an underlying disease, the sooner you find out, the better.

Frequently Asked Questions about cat constipation

How do I know if my cat is constipated? 

Watch for difficulty passing stools, crying and vocalising in the litter box, pooing in the house and being generally off-colour and lethargic.

Can I treat cat constipation at home? 

If your cat’s constipation is mild, you may find that encouraging play and increasing their water intake may get things moving. If not, it’s best to see a vet.

Does dry food cause constipation in cats? 

No. Many cats eat dry food their whole lives and are never constipated. However, if your cat is prone to dehydration or constipation, wet food is a great way to get them to drink extra water. You can also see if they will eat their dry food soaked in warm water. Some cats like the texture, some don’t.

When is cat constipation an emergency? 

If your cat is crying in pain or passing blood, or if the constipation has gone on for more than 48 hours, see your vet as soon as you can. If you have any doubt at all that your cat’s bladder may be blocked and it’s not constipation, this is a medical emergency.

How can I prevent constipation in my cat? 

Keep your cat slim and active, keep them well hydrated, and ask your vet about the best food to feed for your individual cat.

Reviewed by Becky Mullis, DVM, DACVIM (Nutrition) and Emma Milne BVSc FRCVS.