Cat Constipation: Causes, Treatment & When to See a Vet
Cat Constipation Key Facts
If your cat is straining in the litter box, meowing in pain, or hasn't pooped in days, they may be constipated. This common problem can range from a minor issue to a medical emergency. Here's how to tell the difference and what you can do.
Worried about your cat's digestive health?
Upload your cat's bloodwork to check kidney function—the #1 underlying cause of constipation in cats.
Try VetLens FreeHow Often Should Cats Poop?
- Normal frequency: 1-2 times per day
- Still OK: Once every 24-36 hours
- Concerning: No stool for 48 hours
- See a vet: No stool for 72+ hours or straining without producing anything
Normal stool appearance: Formed but not hard, dark brown, doesn't leave residue, easy to scoop.
Signs of Constipation in Cats
Litter Box Behaviors
- Multiple trips to litter box with little or no output
- Straining (crouching, pushing, vocalizing)
- Small, hard, dry fecal balls
- Accidents outside the box
Other Signs
- Decreased appetite
- Lethargy
- Vomiting
- Hard, distended abdomen
- Hiding or acting painful
Straining: Constipation or Urinary Blockage?
What Causes Constipation in Cats?
| Cause | Why It Happens | Risk Factors |
|---|---|---|
| Dehydration | Body reabsorbs water from stool, making it hard | CKD, diabetes, dry food only |
| Diet issues | Low fiber, hairballs, inadequate water | Long-haired cats, dry food |
| Arthritis/pain | Pain prevents normal squatting posture | Senior cats, high-sided litter boxes |
| Megacolon | Colon nerves/muscles fail | Chronic constipation, idiopathic |
| Obesity | Reduced motility, difficult posture | Indoor cats, overfeeding |
| Obstruction | Foreign body, tumor, stricture | Varies |
Home Remedies for Mild Constipation
Important: These are for mild, recent constipation only. If your cat hasn't pooped in 72+ hours, is vomiting, seems in pain, or has a history of urinary issues — see a vet first.
Increase Water Intake
- Add water or low-sodium broth to food
- Switch to wet/canned food exclusively
- Use a water fountain (cats prefer moving water)
- Multiple water bowls around the house
Pumpkin (Plain, Canned)
- 1 teaspoon mixed with food, 1-2x daily
- Must be plain pumpkin, NOT pie filling
- Adds fiber and moisture
- Many cats like the taste
Miralax (Polyethylene Glycol)
- 1/8 to 1/4 teaspoon mixed with wet food, 1-2x daily
- Draws water into stool to soften it
- Safe for short-term use
- Consult vet for ongoing use
Hairball Products
- Laxatone or similar petroleum-based gels
- Helps if hairballs are contributing
- Follow package directions
What NOT to Give
- Milk (most cats are lactose intolerant — causes diarrhea, not productive relief)
- Mineral oil by mouth (aspiration risk)
- Human laxatives without vet approval
- Enemas at home (can cause injury or electrolyte issues)
Is dehydration causing your cat's constipation?
Kidney disease is the #1 cause of chronic dehydration in cats. Upload your cat's bloodwork to check kidney values and catch problems early.
Check Kidney Values NowWhen to See a Vet
Seek Veterinary Care If:
- No bowel movement for 72+ hours
- Straining repeatedly with no stool produced
- Vomiting (especially multiple times)
- Not eating for more than 24 hours
- Painful, distended, or hard abdomen
- Blood in stool or around rectum
- Lethargy or signs of distress
- Previous episodes of constipation
- Known kidney disease or diabetes
Veterinary Treatment Options
Mild-Moderate Cases
- Subcutaneous fluids — Rehydrate the cat
- Lactulose — Prescription stool softener/laxative
- Enema — Given by vet to soften and evacuate stool
- Cost: $100-300
Moderate-Severe Cases
- Manual disimpaction — Under sedation/anesthesia, vet manually removes stool
- IV fluids — For dehydration
- X-rays — To assess severity and rule out obstruction
- Cost: $300-800
Severe/Megacolon Cases
- Hospitalization — IV fluids, repeated enemas
- Motility drugs — Cisapride to help colon contract
- Surgery (subtotal colectomy) — Removes most of colon if megacolon
- Cost: $500-5,000+
Long-Term Management
If your cat has recurring constipation, ongoing management is essential:
Diet Changes
- Wet food only or mostly
- Prescription GI diet (high fiber)
- Daily pumpkin or psyllium fiber
- Add water to all meals
Medications
- Lactulose (daily stool softener)
- Miralax (long-term with vet guidance)
- Cisapride (motility drug)
- Treat underlying conditions (CKD, arthritis)
Environment
- Low-entry litter boxes for arthritic cats
- Clean boxes frequently (cats avoid dirty boxes)
- Water fountains
- Regular exercise/play
Monitoring
- Track bowel movements daily
- Sub-Q fluids at home if prescribed
- Regular vet rechecks
- Bloodwork to monitor kidney function
Megacolon: When the Colon Fails
Megacolon is a condition where the colon becomes abnormally enlarged and loses its ability to contract. It's the most severe form of chronic constipation.
- Causes: Idiopathic (unknown), chronic constipation, pelvic trauma, nerve issues
- Diagnosis: X-rays showing massively dilated colon
- Medical management: Aggressive stool softeners, diet, periodic manual evacuation
- Surgical option: Subtotal colectomy (removing most of colon) — often curative
- Surgery cost: $2,000-5,000
- Post-surgery: Most cats do well; may have softer stools long-term
Cost Summary
| Severity | Cost |
|---|---|
| Mild case (exam, meds) | $100-200 |
| Moderate (enema, sedation) | $300-800 |
| Severe (hospitalization) | $500-1,500 |
| Megacolon surgery | $2,000-5,000 |
| Ongoing management (monthly) | $30-100 |
Related Reading
Monitor Your Cat's Kidney Health
Chronic constipation is often a sign of kidney disease—the most common condition in older cats. Upload your cat's bloodwork to VetLens and get:
- Instant analysis of kidney values (BUN, creatinine, SDMA)
- Plain-English explanations of what results mean
- Trend tracking to catch decline early
- Alerts for values outside normal range
Frequently Asked Questions
How long can a cat go without pooping?
Cats should poop at least once every 24-36 hours. If your cat hasn't pooped in 48-72 hours, it's time to see a vet. Going longer than 72 hours without a bowel movement can lead to serious complications including obstipation (severe impaction).
What can I give my cat for constipation at home?
For mild constipation, try adding water to food, switching to wet food only, or adding a teaspoon of plain canned pumpkin. Miralax (polyethylene glycol) at 1/8 to 1/4 teaspoon twice daily can help. Never give human laxatives without vet approval. See a vet if no improvement in 24-48 hours.
What causes constipation in cats?
Common causes include dehydration (often from kidney disease), low-fiber diet, hairballs, obesity, arthritis (pain prevents squatting), megacolon, pelvic injuries, and certain medications. Older cats and those with CKD are most at risk.
How much does it cost to treat cat constipation?
Treatment costs vary by severity. Mild cases: $100-200 for exam and stool softeners. Moderate (manual extraction): $300-800. Severe/hospitalization: $500-1,500. Megacolon surgery: $2,000-5,000. Ongoing management may cost $30-100/month.
Is my cat constipated or blocked?
If your cat is straining in the litter box, check for urine. No urine (or just tiny drops) in a male cat could indicate a urinary blockage—a life-threatening emergency. Constipated cats usually still urinate normally. When in doubt, see a vet immediately.
Can I give my cat milk for constipation?
No. Most cats are lactose intolerant, so milk will cause diarrhea rather than productive relief. It can also lead to further dehydration and digestive upset. Stick to water, wet food, or vet-approved remedies like pumpkin or Miralax.