---
title: "Cat Constipation"
description: "Straining in the litter box without passing stool for over 48 hours needs vet care in cats. Obese and senior cats are at higher risk."
url: "https://pethealth.org.uk/health/cat-constipation"
canonical: "https://pethealth.org.uk/health/cat-constipation"
date_published: "2026-06-25"
date_modified: "2026-06-25"
source: "PETHEALTH+"
---

# Cat Constipation

**Occasional firm stools are common**, but straining without passing stool for **over 48 hours** needs a vet. Obese, senior, and arthritic cats are at higher risk. Repeated constipation can lead to **megacolon** — a stretched, weak colon that is harder to treat. Vomiting with constipation is urgent.

## Normal toileting vs constipation

Healthy cats pass stool most days — frequency varies with diet. **Constipation** means infrequent, hard, dry faeces or **repeated straining** with little or no result. **Obstipation** is severe blockage where no stool passes despite straining.

**Usually harmless:**

- One slightly firm stool after a **diet change**
- Brief straining that produces a normal stool

**Needs investigation:**

- **No stool for 48 hours** or more
- **Small, hard, dry pellets** repeatedly
- **Straining, crying**, or visiting the tray without result
- Constipation with [vomiting](/health/why-is-my-cat-vomiting) or [not eating](/health/cat-not-eating)
- **Lethargy, bloating**, or painful abdomen when touched

## Common causes in UK cats

| Cause | Typical signs | Notes |
|-------|---------------|-------|
| **Dehydration** | Hard dry stools, reduced urination | Wet food and water fountains help |
| **Obesity** | Infrequent defecation, overweight body | See [Cat obesity UK](/health/cat-obesity-uk) |
| **Arthritis** | Straining, avoiding tray | Pain limits squatting — see [Cat arthritis UK](/health/cat-arthritis-uk) |
| **Pelvic injury** | Chronic constipation after trauma | Narrowed pelvic canal |
| **Hairballs** | Constipation with vomiting fur | See [Cat hairballs](/health/cat-hairballs) |
| **Megacolon** | Recurrent severe constipation | Stretched colon — needs specialist care |
| **Kidney disease** | Dehydration contributing to constipation | See [Kidney disease in cats](/health/kidney-disease-in-cats) |

### Litter box and behaviour factors

Cats may withhold stool if the tray is **dirty**, **moved**, or in a **noisy location**. Stress from new pets or building work can contribute. Rule out behavioural causes alongside medical ones — especially in multi-cat homes.

## When to see a vet urgently

Phone your vet **the same day** or use **emergency out-of-hours care** if:

- **No stool for 48 hours** with repeated straining
- **Vomiting** alongside constipation
- **Bloated, tense, or painful** abdomen
- **Lethargy, collapse**, or not eating for 24 hours
- **Blood** from the rectum after straining
- Known **pelvic fracture** history with worsening signs

Book a **routine appointment within a few days** for recurrent firm stools or mild straining that keeps returning.

## Home care before your appointment

While waiting for a vet visit, note:

- **Last normal stool** — date and appearance
- **Litter box habits** — frequency, straining, locations outside tray
- **Diet** — dry vs wet food, recent changes
- **Mobility** — difficulty jumping or squatting
- **Other symptoms** — [weight loss](/health/cat-weight-loss), [vomiting](/health/why-is-my-cat-vomiting)

**What you can do at home:**

- Ensure **fresh water** — consider a fountain
- Increase **wet food** if your vet agrees
- Keep trays **clean and accessible** — one per cat plus one extra
- **Groom** long-haired cats to reduce hair ingestion
- Monitor **appetite and vomiting**

**What not to do:**

- Do not give **human laxatives or enemas** without vet instruction
- Do not force **large amounts of oil or pumpkin** without advice
- Do not ignore **vomiting with constipation** — this can indicate obstruction

## What your vet may do

Examination may include abdominal palpation, checking hydration, and assessing arthritis or pelvic shape. Your vet might recommend:

- **Enemas or laxatives** — vet prescribed only
- **Hydration support** — fluids under the skin or intravenously
- **Diet change** — fibre-modified or moisture-rich food
- **Pain relief** for arthritis affecting toileting posture
- **Imaging** if obstruction or megacolon is suspected

Treatment depends on severity — mild cases may respond to diet and hydration; obstipation may need hospitalisation. Recurrent constipation should be investigated rather than managed repeatedly at home alone.

## Related guides

- [Cat hairballs](/health/cat-hairballs)
- [Cat obesity UK](/health/cat-obesity-uk)
- [Cat arthritis UK](/health/cat-arthritis-uk)
- [Kidney disease in cats](/health/kidney-disease-in-cats)
- [Why is my cat vomiting?](/health/why-is-my-cat-vomiting)

## FAQs

### Does wet food help cat constipation?

Yes — hydration supports normal stool. Many vets recommend increasing moisture through wet food, fountains, or broth added to meals as part of a management plan.

### Can hairballs cause constipation?

Large hairballs can contribute to blockage, especially in long-haired cats. Regular grooming and hairball diets may help — ask your vet if constipation recurs.

### Is pumpkin safe for constipated cats?

Plain cooked pumpkin in small amounts may add fibre — but only use if your vet agrees. It is not a substitute for treatment if your cat has not passed stool for 48 hours.

### When is constipation an emergency?

Vomiting, bloating, repeated straining with no stool for 48 hours or more, or a painful abdomen needs urgent vet care — obstipation can become life-threatening.

## Sources

- [PDSA — Cat health advice](https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub)
- [Blue Cross — Cat advice](https://www.bluecross.org.uk/pet-advice)
- [Cats Protection — Health advice](https://www.cats.org.uk/help-and-advice)

Canonical HTML: https://pethealth.org.uk/health/cat-constipation
Last modified: 2026-06-25