Cat Constipation: How Long Can a Cat Go Without Pooping?

Most cats poop about once a day. If your cat hasn't passed any stool within 48 to 72 hours of the last one, or seems uncomfortable before then, call your vet. And if your cat keeps squatting and straining in the litter box with little or nothing coming out, especially a male cat, call now, day or night: that can be a blocked bladder, not constipation, and a blocked cat can die within a day or two.

Constipation is common in cats and easier to sort out when it's caught early. The hard part is that a constipated cat and a blocked cat can look the same from the doorway, so here's how to tell which call to make.

How long can a cat go without pooping?

A healthy adult cat usually passes stool about once a day. A day without a bowel movement can happen. Two to three days is where it stops being a wait-and-see question: VCA Animal Hospitals and PetMD both advise calling your veterinarian if your cat hasn't had a bowel movement within 48 to 72 hours of the previous one.

That window is the outside limit, not a countdown. To be on the safe side, call sooner if your cat:

• is straining, crying or going in and out of the box without producing anything
• is vomiting, off food or hiding
• has a tense or painful belly
• is a senior, has chronic kidney disease, has had constipation or megacolon before, or recently started a new medication

Waiting has a cost. The longer stool sits in the colon, the more water it loses and the harder it gets to pass. Constipation that drags on or keeps coming back can stretch the colon until it no longer contracts properly, a condition called megacolon that sometimes ends in surgery.

Constipated or blocked? Why straining can be an emergency

A cat hunched and pushing in the litter box could be trying to poop or to pee. International Cat Care points out that the two are hard to tell apart by watching, and one of them is an emergency.

Urethral obstruction means the tube that carries urine out of the bladder is blocked, often by a plug of minerals, cells and mucus or by a small stone. It happens almost only in male cats, whose urethra is longer and narrower. The bladder keeps filling, toxins build up in the blood, and the Cornell Feline Health Center warns that the time from complete blockage to death may be less than 24 to 48 hours.

Signs of a blocked cat, according to iCatCare:

• repeated trips to the box with nothing or only drops of urine
• crying or obvious pain while straining
• peeing outside the box
• restlessness, licking at the genitals
• refusing food, vomiting, seeming flat

If your cat is straining and you can't find fresh urine clumps in the litter, treat it as a blockage and call your vet or an emergency clinic now. Don't try to sort it out by feeling the belly at home: pressing on a blocked bladder hurts, and only a hands-on exam by your vet can tell the difference safely. Our guide to feline lower urinary tract disease explains the causes.

What is constipation in cats?

The Merck Veterinary Manual defines constipation as "the infrequent or difficult evacuation of feces, which are typically dry and hard." The colon pulls water out of stool, so the longer stool stays there, the drier and harder it gets. Normal cat poop is brown, formed and moist.

Two related terms you may hear from your vet:

• Obstipation: constipation so severe that the cat can't pass the hard mass at all. It usually needs veterinary treatment to clear.
• Megacolon: a colon that has become stretched, weak and unable to push stool out. It can follow long-term constipation and obstipation, or appear with no known cause (idiopathic megacolon).

What causes constipation in cats?

Most constipated cats have a mix of factors. Merck lists older cats, overweight cats, cats with chronic kidney disease (which keeps them mildly dehydrated) and cats with earlier episodes as most at risk. Common contributors:

• Not enough water. Dehydration is one of the biggest. Cats on a mostly dry diet and cats with kidney disease are more likely to have dry, hard stool.
• Hair and other indigestible material. Hair from grooming, bones or litter can mix with stool and form a firm mass, especially in long-haired cats.
• Not wanting to use the box. A dirty box, a box shared with a bully, a disliked litter, a noisy spot or stress from a move or a new pet can make a cat hold it in.
• Pain. Arthritis can make climbing into the box and squatting hurt, so stiff older cats may go less often.
• A narrowed or blocked colon. An old pelvic fracture, a stricture, a tumor or a foreign body can physically get in the way.
• Nerve and metabolic problems. Spinal or tail-pull injuries, dysautonomia (a nervous system disorder), low potassium, high calcium and, rarely in cats, low thyroid hormone.
• Medications. Some drugs slow the gut, including opioid pain relievers, diuretics and antihistamines. Don't stop a prescribed drug; ask your vet whether it could be playing a part.
• Extra weight and too little activity raise the risk too.

Arais, who wrote the first version of this guide, saw this with her own foster cat, Lady: she was straining and passing small, hard, dry stools, and in her case the cause was dehydration.

Signs of constipation in cats

The classic sign is straining to defecate, which vets call tenesmus. Other signs:

• small, hard, dry stools, or none at all
• going in and out of the box, digging and spending a long time there
• crying or growling while trying to pass stool
• passing stool outside the box
• a little liquid stool, sometimes with mucus or a streak of blood, that squeezes past a hard mass and is easily mistaken for diarrhea
• eating less, vomiting, lethargy or hiding

Cats hide discomfort well, so the litter box is often your best clue. In a multi-cat home, check whose stools you're actually scooping.

What your vet will do

Before the visit, jot down what you've seen. Your history helps your vet as much as the exam does:

• when your cat last passed a normal stool, and what it looked like
• whether your cat is still peeing, and how much
• any vomiting or appetite change
• diet, recent food changes and how much your cat drinks
• current medications and past injuries, such as a pelvic fracture

At the clinic, your vet will feel your cat's belly for stool in the colon or a full bladder and usually do a rectal exam. Depending on what they find, they may suggest:

• X-rays to see how much stool is in the colon, whether the colon is enlarged, and whether an old pelvic fracture is narrowing the way out
• blood and urine tests for dehydration, kidney disease and other underlying problems
• ultrasound or colonoscopy in cats with repeated constipation, to look for masses or strictures

Treatment depends on the cause and how severe it is. Your vet may use:

• fluids, often through an IV, to correct dehydration
• an enema given at the clinic, often with the cat sedated
• manual removal of the stool under general anesthesia for hard, impacted feces, sometimes over more than one session
• a diet change, laxatives or drugs that help the colon contract, chosen and dosed by your vet for your cat
• surgery to remove most of the colon (subtotal colectomy) when megacolon doesn't respond to medical treatment, or to remove an obstruction such as a foreign body. Most cats do well after it.

Why human enemas and laxatives are off the table

Please don't reach for something from the pharmacy. Merck warns that phosphate-containing enemas must be avoided in cats because they can cause life-threatening changes in blood salts, and as Liz Bales, VMD, told PetMD, giving a cat an enema "is a veterinary job and should not be attempted at home." Laxatives can also worsen dehydration, and stimulant types are dangerous if the colon is blocked, so your vet rules out an obstruction first and then picks any product and dose.

How to help a constipated cat at home (safely)

These steps support your vet's plan and help prevent the next episode. They don't replace a vet visit for a cat that's straining or hasn't pooped in two to three days.

1. Get more water into your cat. Wet food is the easiest way, because it adds water to every meal. Offer several wide, shallow bowls (glass or ceramic, filled to the brim) in quiet spots away from the food, at least one per cat plus one. Some cats like a fountain.
2. Make the litter box easy to use. The AAHA/AAFP feline guidelines recommend one box per cat plus one, in different quiet places, scooped every day. Stiff, older cats manage better with a low-sided box. Never punish a cat for going outside the box.
3. Keep your cat moving. Daily play and climbing spots help the gut and ease stress.
4. Work toward a healthy weight with your vet, who can tell you whether your cat needs to lose any and set a safe plan.
5. Brush often, especially long-haired cats, so less swallowed hair ends up in the colon.
6. Ask your vet before adding fiber or pumpkin.

What about massage or acupuncture? Good evidence in cats is lacking, so treat them as add-ons to discuss with your vet, never a substitute for an exam. Gentle stroking your cat enjoys is fine; pressing on a sore belly is not.

Newborn kittens are different

Very young kittens can't pee or poop on their own; their mother licks them to make them go. If you're caring for orphaned kittens, you'll need to gently stimulate them with a soft, warm, damp cloth at each feeding, or they can become constipated and run into urinary problems. Kitten Lady shows how:

A kitten that strains, cries, has a swollen belly or stops eating needs a vet the same day.

Quick answers

Is it an emergency if my cat hasn't pooped in 3 days? It needs a vet visit, so call today. If your cat is also straining with no urine, vomiting or very quiet, call now.

Will constipation go away on its own? A day without stool can happen in a healthy cat. Constipation that lasts or keeps coming back can damage the colon, which is why it's worth treating early.

If your dog is the one with the problem, see our guide on how long a dog can go without pooping.

Originally written by Arais. Updated by the I Love Veterinary editorial team.

Sources

• Merck Veterinary Manual: Constipation, Obstipation, and Megacolon in Small Animals
• International Cat Care: Constipation in cats
• International Cat Care: Urethral obstruction in cats
• International Cat Care: How to encourage your cat to drink
• Cornell Feline Health Center: Feline Lower Urinary Tract Disease
• AAHA/AAFP 2021 Feline Life Stage Guidelines: General Litter Box Considerations
• VCA Animal Hospitals: Constipation in Cats
• PetMD: How To Treat Constipation in Cats
• Kitten Lady: Stimulating Kittens

This article is for general information and is not a substitute for advice from your veterinarian.