Cat Constipation: Vet Advice on Causes, Care and When to Worry

Cats can be hard to read when something’s up. They don’t always make it obvious when they’re uncomfortable, but the litter tray doesn’t lie.

Constipation is one of those issues that often builds up quietly. One skipped poo turns into two. Then you hear straining, or find small, hard lumps in the tray. 

At the clinic, I observe constipation in cats in numerous situations, from young ones adapting to solid food to older ones where joint issues make using the litter tray painful, and also in house cats that have changed their litter tray habits after moving or experiencing a change in their daily life.

This guide walks you through what causes constipation in cats, how to help at home, what to feed, and when it’s time to get your vet involved. The earlier you catch it, the easier it is to fix.

Most cats will poo once every day or so. Their stool should be well-formed, smooth, and easy to scoop. If your cat hasn’t gone in a while, or if you’re noticing changes in the litter tray, it’s worth paying attention.

Common signs of constipation in cats:

• Straining to poo but not producing anything
• Passing small, dry, hard stools
• Going less often than usual
• Avoiding the litter tray
• Crouching, meowing, or tensing when trying to go
• Vomiting, hiding, or losing interest in food

Cat constipation happens when poo becomes too dry, too hard, or too difficult to pass. Most of the time, it’s caused by a few simple things stacking up, like not drinking enough, swallowing too much hair, or not being active enough.

Not Enough Water

Cats who eat mainly dry cat food may find it a little harder to stay hydrated. Without moisture, their stool dries out and becomes harder to pass.

Swallowing Fur

Grooming is a big part of a cat's life. But all that licking means they swallow hair, which can build up in the gut and slow things down. Long-haired cats are especially prone.

Stress or Routine Changes

Cats are sensitive to change. Moving house, new pets, or a dirty litter tray can all make them hold in their stool. That can lead to constipation over time.

Low Activity

Indoor cats, older cats, or cats recovering from surgery may not move around much, and movement helps keep digestion on track.

Medication Side Effects

Some painkillers or anti-nausea medications can slow the gut. If your cat becomes constipated after a procedure, check with your vet.

Underlying Health Issues

Repeat constipation could be linked to:

• Arthritis (if it hurts to squat)
• Obesity
• Pelvic injuries
• Megacolon
• Kidney disease or diabetes
• Blocked anal glands

Food and hydration are key to getting things moving again. Think soft, moist, and easy-to-digest.

Bland, Fibre-Rich Meals (short-term solution)

If your cat is eating and behaving normally, try this gentle, stool-softening home remedy for cat constipation:

• Wet food (with added water or low-sodium broth without any seasonings)
• Plain cooked pumpkin (½ to 1 tsp)
• Boiled chicken (skinless, unseasoned)
• A small amount of mashed sweet potato or carrot

Try to avoid dry biscuits and treats until stools return to normal.

High-Fibre or Digestive Care Diets (long-term support)

For cats who get constipated often, a vet-approved diet may help:

• Wet or mixed (wet + dry) feeding to boost hydration
• Fibre-enhanced or digestive care cat food formulas
• Prescription diets for chronic constipation
• Added cat probiotics to support gut health

Work with your vet to find the right approach for your cat.

Mild cases often improve with a few small changes. Here’s what to try:

Add a bit of fibre

Mix ½ to 1 tsp of plain pumpkin into your cat’s meals. You can also ask your vet about a safe fibre supplement like psyllium husk.

Boost hydration

Add warm water or broth to food. Offer extra water bowls or try a pet fountain; some cats prefer moving water.

Encourage movement

A bit of playtime can go a long way. Toss a cat toy, use a laser pointer, or get them moving with a short interactive session. For healthy cats, cat towers or high ledges can encourage climbing and outdoor enclosed housing or runs can also encourage activity.

Monitor closely

Track when they last pooped, how the stool looks, and whether they’re straining or avoiding the tray. Keep a note if you need to call your vet.

Not all constipation can be managed at home. Get in touch with your vet if your cat:

• Hasn’t pooed in 48+ hours
• Is straining but not producing stool
• Seems bloated, in pain, or lethargic
• Is vomiting or off their food
• Has hard or bloody stool
• Gets constipated frequently

In more serious cases, constipation can lead to obstipation: a complete blockage that requires medical treatment or even surgery. The earlier you step in, the easier it is to treat.

Your vet will gently examine your cat’s belly and may do a rectal exam or take X-rays. They’ll want to know:

• When your cat last passed a normal stool
• Stool appearance (size, shape, texture)
• What your cat eats and drinks
• Any recent changes in routine, meds, or litter habits

If there’s any chance your cat has eaten something other than food (favourites are hair ties and at Christmas beware of tinsel)

Treatment might include:

• A vet-administered enema or stool removal
• Fluids to treat dehydration
• Laxatives or stool softeners
• Diet changes or fibre supplements
• Tests to check for underlying conditions