It can be really heart-breaking and worrying watching your cat struggling to use their litter tray, especially when they’re distressed or crying. If your cat is visiting the tray more often than usual, it’s important to take a closer look at what they’re producing (or, more importantly, what they’re not), then pop them to the vets.

Constipation is very uncomfortable and needs treatment, but the symptoms are also very similar to a cat struggling to urinate, which may be an emergency. A quick scout of the litter tray for faeces, urine and blood will help your vet determine exactly what is wrong when you call.

Other than frequent visits to the tray, what other symptoms should you be on the look out for?

Constipated cats will hunch over and try to defecate, whether in the tray or elsewhere. They may cry in distress, although not always. They may also start to vomit. Many affected cats will not eat and may also be lethargic. If they produce anything at all, the faeces are likely to be dry and hard and maybe in smaller sections than usual; more like rabbit faeces than cat faeces. Unless your cat has access to the outside or likes to toilet elsewhere, they should be producing 1-2 poos daily in their tray. More or less than this may be a cause for concern, although could also be normal for your cat – every cat is different after all!

Once you’re at the vets, they can feel your cat’s abdomen for evidence of constipation. They may suggest some testing, such as an x-ray or blood tests, and will talk through your treatment options. Mild cases of constipation may be relieved with laxatives, but some may require an enema. Constipation is usually caused by an underlying disease, so figuring out what’s causing it is an important part of treatment.

So what could be causing your cat’s constipation?


The most common cause of constipation is dehydration. Of course, dehydration in itself is also a symptom and can have many causes. Getting to the root cause of your cat’s dehydration is important, as underlying diseases such as kidney disease and hyperthyroidism can cause dehydration, especially in older cats. Cats are pretty terrible at drinking enough water (just like most humans I know!) and may need some encouragement. Providing water fountains and plenty of different bowls are good ways to persuade your cat to drink a little more often.

Hairballs and other Foreign Bodies

Although hairballs don’t cause a problem for most cats, they can compact and cause constipation in cats that have an underlying condition, causing dehydration or a narrowed pelvic canal. Hairballs are most common in cats that have long fur or who are grooming more than usual due to itchiness or stress. Feeding a daily feline laxative can ensure that hairballs keep moving and don’t cause constipation.

Cats are much less prone to eating foreign bodies than dogs are, but it’s not unheard of. Like hairballs, foreign bodies can compact and make a constipation problem much worse.

Pain whilst toileting

Cats that have pain toileting will hold their faeces for as long as possible, sometimes causing constipation. This may be true of cats who are arthritic (which is a surprisingly high 80-90% of cats over 14 years) who might find it hard to climb into a tray or assume the correct squatting position. Other causes of pain that might prevent a cat from wanting to use the toilet include impacted anal glands (thankfully rare in cats), wounds and trauma to the tail and back end (cat bites in this area are fairly common), and recent diarrhoea causing an inflamed rectum. If this is the cause of your cat’s constipation, pain relief is usually required. In the case of arthritis, other treatments such as joint supplements and laser therapy may also be recommended.

Narrowed pelvis

As the faeces move through the pelvis, the colon and rectum are able to expand and stretch slightly, allowing larger and bulkier faeces to move through. Cats that have had fractures to their pelvis may have a narrowed canal, which means there’s no space for the gut to stretch. Bulky faeces can get stuck in the area, causing constipation and pain.

There’s no treatment for this type of narrowed pelvic canal, so management is about keeping the faeces soft and able to pass, usually by long-term use of laxatives.

Obesity is also a cause of a narrowed canal and inability of the body to move faeces around appropriately. If this is the cause, then a structured weight loss plan could make a lot of difference to your cat’s quality of life.


Although rare, megacolon is a disease to consider when identifying a cause of constipation. For an unknown reason, the muscles of the colon cease to work effectively, causing the colon to become slack and unable to move faeces around properly. Interestingly, megacolon is also occasionally caused by unresolved constipation – another good reason to get your cat seen by a vet sooner rather than later.


Any reason that a cat is prevented from using the tray can cause them to become constipated. In this case, fear can cause them to hold onto their faeces rather than use the tray. If your young cat is becoming constipated and doesn’t fit into any of the other categories in this article, behaviour is most likely to be causing the problem.

Cats need quiet, private places to toilet, so placing the tray in a quiet space is important. You should have one litter tray per cat and one spare, and they should be spread throughout the house. This is important because, in a fit of meanness, a bully cat can block access to a tray, causing the fearful cat to hold on to their faeces and cause constipation. Trays should also be out of sight of windows and outside doors to prevent a neighbourhood bully from staring threateningly whilst your cat is trying to toilet.

Although this list contains many of the causes of constipation, there are likely to be many more in individual cases. Good communication with your vet will help to identify the cause of constipation in your cat so that you can focus on treating the underlying disease.

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