The most common reason: the box itself is the problem
Cats stop using the litter box for poop more often because of the box than because of the cat. A box that is too small, too dirty, placed in a noisy or high-traffic area, or filled with litter your cat dislikes will send them looking elsewhere. The box needs to be at least 1.5 times the length of your cat's body, and many cats prefer even larger ones.
Cleanliness matters more for poop than for urine. Cats are particular about where they defecate, and a box with old waste in it—even if you scooped urine—may feel unacceptable. Scoop poop daily and do a full litter change at least weekly. If you have multiple cats, the rule is one box per cat plus one extra, all in different locations.
The type of litter also plays a role. Some cats dislike clay litter, scented litter, or litter that has changed brands recently. If you switched litters and the problem started, that is likely the cause. Try going back to the old brand or offering a second box with a different litter type so your cat can choose.
Key Takeaways
- The litter box itself is the cause in most cases—size, cleanliness, location, or litter type can all trigger the behavior.
- Medical problems like digestive issues, parasites, or inflammatory bowel disease require a vet visit and are more likely if the behavior is new.
- Stress from household changes, new pets, or loud noises can make cats avoid the box, even if nothing physical is wrong.
- You need one box per cat plus one extra, placed in quiet, accessible areas away from food and water bowls.
- If your cat uses the box for urine but not poop, the issue is usually litter preference or box cleanliness rather than a medical emergency.
Medical reasons your cat may avoid the box
If the behavior is new and your cat was reliable before, a vet visit should be your first step. Digestive problems, parasites, food allergies, and inflammatory bowel disease all cause cats to poop outside the box. Cats sometimes avoid the box because defecating in it causes pain or discomfort, and they associate the box with that pain.
Older cats may have arthritis that makes climbing into a high-sided box difficult, or they may lose control and need to go quickly. Senior cats benefit from boxes with lower sides or ramps. Constipation or diarrhea can also make a cat feel urgent or unpredictable about where they go.
A vet can rule out parasites, food sensitivities, and intestinal inflammation with a physical exam and sometimes a stool sample. If your cat has other signs—weight loss, vomiting, changes in appetite, or straining—mention those when you call. These details help the vet narrow down the cause faster.
Stress and anxiety as triggers
Cats are sensitive to change. A new pet, a move, construction noise, a new family member, or even rearranged furniture can stress a cat enough to stop using the box reliably. Some cats respond to stress by urinating outside the box; others respond by pooping outside it. The behavior is a sign your cat feels unsafe or overwhelmed.
Identify what changed recently. Did you bring home a new cat or dog? Did someone move in? Did you renovate a room? Once you know the stressor, you can work to reduce it—keeping the new pet separated at first, using calming pheromone diffusers like Feliway, or creating a quiet, safe space where your cat can retreat.
If stress is the cause, the behavior usually improves once your cat adjusts, but that can take weeks or months. In the meantime, make sure the litter box is in a place where your cat feels safe and can see approaching threats. A box in a corner with an escape route nearby is less stressful than one in the middle of a room.
Litter box location and setup mistakes
Where you place the box matters as much as what is in it. A box next to a loud appliance like a washing machine or furnace can startle your cat mid-poop, creating a negative association. A box in a high-traffic area where the cat feels exposed or interrupted will be avoided. Cats need privacy and quiet to feel comfortable defecating.
Never place the box near the food and water bowls. Cats are naturally clean animals and dislike eliminating near where they eat. If your setup has the box close to food, move it to a different room or at least several feet away. In a small apartment, this may mean putting the box in a bathroom and the food in the kitchen, even if they are close.
Make sure the box is straightforward to reach. A box in a basement that requires going down stairs, or one blocked by a door that closes, may be inaccessible when your cat needs it urgently. Older or very young cats especially need boxes on the same floor where they spend most of their time.
When your cat uses the box for urine but not poop
This pattern—peeing in the box but pooping elsewhere—is usually about litter preference or cleanliness rather than a medical issue. Cats often have different preferences for where they urinate versus where they defecate. Some cats will use a dirty box for urine but refuse to poop in it.
Try adding a second box in a different location with a different litter type. Use a finer-grained litter, or switch to pelleted litter, or try a brand without scent. Offer your cat options and watch which one they choose. Once you see a preference, you can adjust the other boxes to match.
Also check the depth of litter in the box. Some cats prefer shallow litter for poop—about 2 inches—while others want deeper litter for urine. If you have been filling the box deeply, try reducing the depth and see if the behavior improves.
How to retrain your cat to use the box
Once you have identified and fixed the underlying problem—whether that is box size, cleanliness, location, or litter type—your cat will usually return to the box on their own. Do not punish accidents; punishment creates fear and makes the problem worse. Instead, clean soiled areas thoroughly with an enzymatic cleaner to remove the scent, which otherwise signals to your cat that the spot is a toilet.
If accidents continue after you have made changes, confine your cat to a smaller space with the litter box for a few days. A bathroom or bedroom works well. This forces proximity to the box and often resets the habit. Once your cat is using the box reliably in the confined space, gradually expand their access to the rest of the house.
Praise and reward your cat when you see them use the box. A treat or a few seconds of petting right after they finish reinforces the behavior. Positive reinforcement works better than punishment for litter box issues.
When to call the vet
Contact your vet if the behavior is new, if your cat is straining or seems to be in pain, if there is blood in the stool, or if the problem persists after you have made environmental changes. Also call if your cat is older, has lost weight, or has other signs of illness. A vet can rule out medical causes and give you confidence that the problem is behavioral.
If your cat has always been reliable and suddenly starts pooping outside the box, that is a stronger signal of a medical issue than if the behavior has been occasional since kittenhood. New behavior warrants a vet visit; lifelong habits are more likely to be preference or learned behavior.
Frequently Asked Questions
Is my cat pooping outside the box because they are angry at me?
No. Cats do not poop outside the box as punishment or spite. They do it because the box is uncomfortable, inaccessible, or unclean; because they have a medical problem; or because they are stressed. Assuming anger will lead you to punish your cat, which makes the problem worse. Focus on the box and the environment instead.
Should I use a covered litter box?
Many cats dislike covered boxes because they trap odor and make the cat feel trapped. If your cat is pooping outside the box and you have a covered box, try removing the cover or switching to an open box. Some cats prefer covered boxes, but if there is a problem, an open box is usually the safer choice.
Can I use the same box for multiple cats?
You can, but it is not ideal. Cats prefer separate boxes, and sharing increases the chance that one cat will avoid it because it smells like another cat's waste. The standard rule is one box per cat plus one extra. If space is limited, at least place boxes in different rooms so each cat has a private option.
How often should I completely change the litter?
Scoop poop and clumped urine daily, and do a full litter change at least once a week. Some cats are pickier and need a full change twice a week. If your cat is pooping outside the box, try increasing to twice-weekly changes and see if the behavior improves.
What if my cat poops outside the box but pees in it?
This usually means your cat dislikes the litter for poop specifically, or the box is not clean enough for their standards about defecation. Try a finer or shallower litter, clean the box more often, or add a second box with different litter. Most cats will switch back once they find a setup they prefer.