Cat Constipation 101 (causes, home treatment + prevention)

Constipation in cats is a pretty common problem. Understanding the causes of constipation will help you give your cat the treatment they need, and also help prevent the problem in the future.

It might be as easy as giving a simple home remedy or making a small change in your house!

treating cat constipation with picture of cat standing by litter tray

My cat’s stools are very hard and he is constipated and very uncomfortable. He was on Chronulac oral. Is there anything I can give him until I get to the vet?

Causes of Cat Constipation

  • Dehydration - can be due to kidney disease, diabetes + hyperthyroidism

  • Megacolon or other intestinal disease

  • Narrow pelvis - due to pelvic fracture or tumors

  • Pain - caused by arthritis or anal gland disease

  • Stool contents - lots of bone or hair

  • Stress - causing a cat to hold on for long periods

The home treatment of constipation in cats is really going to depend, to a certain extent, on what the causes of constipation is in each individual cat. And there are a number of different causes.

So we can get dehydration, and this is probably the most common, especially in an older cat. This dehydration is often caused by another disease like kidney disease, diabetes, or hyperthyroidism being an underlying problem.

So much like the last question about a dog on steroids drinking more, The situation is similar here. If we've got an underlying condition like kidney disease or diabetes, that's going to be causing a cat to produce a lot more dilute urine and as a result it can be difficult for them to maintain their hydration.

They simply can’t drink enough to stay hydrated.

Other causes include intestinal disease, with a condition called megacolon being one of the most common. This is effectively when the colon, or the back-end of the intestinal tract, stops being able to contract effectively. It stops being able to move the fecal material through the intestines and out the other end.

Previous pelvic fractures or tumors can also cause problems because they can actually cause a narrowing of the pelvic canal. This causes problems with a cat passing feces and so constipation as the stools simply have a problem fitting through the narrower passageway.

Arthritis, anal gland disease, or other painful conditions can also cause constipation. They can cause a reduction in the desire to defecate. If a cat knows that it's going to hurt when they go to the toilet, they’re going to hold on for longer and longer. As a result, the stools build up and then dry out, resulting in a cat becoming constipated.

Also, another constipation cause is if there's something abnormal actually within the stool. This could be bones, little bone fragments. It could be a lot of hair if your cat’s a chronic groomer or they've got long hair and that's building up. These can cause an abnormality in the stool and again, it gets stuck, gets dry and we get some severe constipation.

Finally, stress can also cause a problem with constipation in cats. If there's not enough litter boxes, or if there's no way to toilet, again, a cat's going to hold on for as long as they can before they go. And that's going to cause problems passing their stool when they eventually try to toilet.

Treating Constipation in Cats

So what can we do about treating cat constipation at home?


Lactulose, which is what this cat is on, is a very good laxative. It's actually a synthetic sugar, which isn't absorbed by the gut, but instead it acts to pull water into the colon. This prevents the stool from drying out, softens the poop, and then improves its passage through the bowel.

Lactulose often does a very good job, although the dose needs to vary quite a lot. We need to give it to effect. If we're producing diarrhea than you're giving too much, but if the stool is still really firm and we're still having problems, then we can always give it at a higher dose or a little bit more frequently.

Clearly this is something that you're going to want to be talking to your vet about. It’s also important to give it to your cat without forcing it in rapidly. Lactulose can be breathed in and cause serious problems if it gets into the lungs.

Diet change (FIBER)

Adding fiber is something that can also help.

Fiber is really important for colon health. It improves contractions as well, and so can treat constipation. Now, you can add fiber to your cat’s diet in a number of different ways. You can give Metamucil, add wheat bran, or even add canned pumpkin to the food. These can all help.

Conversely though with cats, and cats being a bit more of a challenge sometimes than dogs (!), some cats will actually respond better to having a low fiber diet. An idea here then is assessing what your cat is currently being fed, how much fiber is in their diet, and if they are already being fed a high fibber diet, then try changing to a much lower fiber diet. But if they're being fed a normal food, which is generally quite low in fiber, then actually adding more, or feeding a specific high fiber diet may certainly help.


Hydration is key. Simple!

Dehydration is a major cause of cat constipation, and a lot of laxatives work by drawing water into the intestines, and softening the stools. If you’re cat is already fully hydrated then that's going to help prevent any constipation in the first place, as well as help make any laxative treatment more efficient.

You can increase our cat's water intake a number of different ways:

  • Feeding wet food

  • Add water to the food

  • Add fresh water to different types of bowls (plastic/glass/metal)

  • Trying bottled or filtered water rather than tap water

  • Make a broth (low salt)

  • Running water can really help (like using one of these fantastic cat fountains)

    Now I've actually got a separate article that I'll link to in the show notes that goes through all of the different ways about how to get a cat to drink more water. So if you're struggling with this for your cat, then I'd encourage you to check that out.

If you want to learn more (and I’d strongly recomend it), I've actually written a separate article that runs through the top 10 ways for how to get a cat to drink more water.

Litter tray management

And then other things that we can do is to make sure that there are enough litter trays so that your cat is not having to hold on. Also, make sure that your cat can easily access them. So if you've got an older cat who's arthritic this can be a major problem. A lot of litter trays have quite high ramps, or if it's enclosed have a narrow entrance. This can really cause an arthritis cat problems actually accessing their tray in the first instance.

Try and use a tray with a lower lip, or use a ramp so that it's easier for your cat to get up into it.

Also experiment with litter type, make sure they are cleaned daily. As for number, there should be one more litter tray than the number of cats in the house.


Also, exercise can help to mobilize the stool and so treat or prevent constipation. Depending on what your cat enjoys doing, this could involve playing with a mouse on a string or whatever it is they like to be doing.

Treat any other diseases

And then finally, just to make sure that we're treating any other conditions as well. So like arthritis, we want to be making sure that their are treatments in place for the other conditions. So are they getting an anti-inflammatory painkiller? Are they getting a kidney diet to treat their kidney disease? Are they getting insulin to treat their diabetes and is that treatment effective and working well?


So I hope this gives you a few ideas of how we can go about treating constipation in cats. Understanding what caused the constipation in the first place will help you not only treat it, but also help prevent it in the future with some simple home remedies and environmental or management changes.

For those cats that are severely constipated, an enema and hospitalization for intravenous fluid re-hydration along with any other required treatments may be the only option. Because constipation can be this serious, and there is often an underlying disease causing it, getting your cat checked over by your vet is always a good idea.

It’s also important to note that a bladder problem can also be mistaken as constipation. This can even be fatal in a male cat with a blocked bladder!

The above is a transcript taken from “The Dr Alex Answers Show”.

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