Your cat could be pooping outside the litter box for a variety of reasons, including health problems, stress, a smelly litter box, the litter box in the wrong spot, a change in their household, or a new family member. If the behavior continues to happen for an extended period of time, it's best to take your cat to the vet so they can determine if your cat has a health issue or if a behavioral issue needs to be addressed.
Changes in the home, such as a new pet or baby, a move to a new location, or a sudden change in family routine can also cause a cat to refuse to use their litter box, and instead, showing their stress by pooping on the floor.
Most often, litter box problems are caused by a change in the cat's routine or issues with its litter box. But if your house-trained cat suddenly stops using its box, your first step is to take your kitty to the vet to rule out any health issues.
Sometimes if your cat has diarrhea or constipation, the urge to go may be sudden and overwhelming, and they may not make it to the litter box in time. This situation should be temporary, however, provided your kitty has no underlying health conditions.
Older cats with arthritis might have pain and difficulty in climbing into the box, and so they might relieve themselves on the floor next to it instead. Your vet should be able to give you solutions on how to accommodate your aging kitty.
If your vet determines that your cat is healthy, she'll probably move on to exploring whether your cat has a behavioral problem.
Smelly Litter Box
It's very common for cats to turn up their noses at a litter box if it doesn't meet their exacting standards for cleanliness and odor. If it's not pristine, even cats that have been litter trained for years may reject the box in favor of another area (usually one that will get your attention).
If you change the type of litter you use, your cat might not like the texture or new scent and will avoid the litter box.
Wrong Box Location
Is the location of the litter box problematic for your cat? If it's near a door or in a part of the house that gets a lot of traffic or that the cat can't easily get to, consider moving it. Just like humans, cats want privacy when they have to go. However, moving the litter box isn't recommended if your cat has dementia, as it may create more confusion.
Change in the Household
If another cat, animal, or even a new baby has been introduced to the household or if someone has moved in, moved out, or moved on, your cat may simply be marking their territory. This should be temporary until the cat gets used to the new situation. But be aware that any change to a cat's routine or environment can cause stress, which may result in out-of-the-ordinary behavior.
Recently Adopted Kitty
A cat that's been recently adopted may take a few weeks or months to fully adjust and feel comfortable enough to reveal their personality. It may be that your adoptive cat was feeling a bit uncertain at first and was willing to share the litter box but later changed their mind. Make sure your new cat knows where their litter boxes are kept and that they have easy access to them.
Just like humans, cats can get stressed when their normal environment and routine gets disrupted. If you've recently moved, there's construction happening outside your house, or your cat's usual space has been disrupted in any way, they will probably experience some stress and can act in ways that are unusual for them, such as pooping outside their litter box.
How to Stop Your Cat From Pooping Outside the Litter Box
Clean the Box
First and foremost, scoop clumps from the litter box daily and deep clean it frequently. This means jettisoning the old litter, scrubbing the empty box with mild dish soap and warm water, rinsing it with clean water, letting it air-dry, and pouring in a fresh supply of clean, unscented litter (sometimes scented litter is unappealing to finicky cats). Whenever you handle your kitty's litter box, always use rubber gloves and a face mask to protect yourself from microscopic bugs and litter dust.
If you're pregnant, leave all litter box maintenance to another member of the household to reduce your risk of contracting toxoplasmosis.
Focus on Location
If you find that your cat is drawn to using a particular spot, such as a bath mat, try to block access to the room by setting up a baby gate or closing/locking the door whenever possible. At the same time, encourage your pet to use their litter box as intended by locating the box well away from their food and water bowls in a quiet, private area that's easy to get to.
Add Another Litter Box
If you've added a second cat, consider installing additional litter boxes rather than trying to make both cats share a box. The optimal number of litter boxes is one for each cat plus one more. This means that if you have two cats, you should provide three litter boxes. Note that the boxes need to be in totally different places. Otherwise, one cat may attempt to "guard" and own all the toilets and keep the other cat away.
Put Up Obstacles
If there's a particular area where your cat has been going frequently and you can't block their access, try laying down aluminum foil or spray the area with a kitty-safe deterrent. The goal is to make the inappropriate area as undesirable to the cat as possible.
Re-Create the Scene of the Crime
Take a look at the surface where your cat prefers to poop and try duplicating that surface in the litter box. For instance, if your kitty likes tile, leave the bottom of the litter box bare. If they target paper, line the bottom of the box with paper; if they go on carpeting, install a carpet remnant in the box.
Clean Up Previous Accidents
If, in spite of your best efforts, your cat poops outside the litter box for any reason, thoroughly clean the area with an enzymatic cleaner so your kitty doesn't catch the scent and think it's OK to go there again.
When to Call the Vet
If your cat has one accident and then the next day they are back to using the litter box as normal, it shouldn't be anything to worry about. However, if your cat continues to poop outside the litter box for multiple days in a row, it's time to head to the vet to make sure your cat doesn't have any underlying health conditions.
Feline Behavior Problems: House Soiling. Cornell Feline Health Center
Why Isn't My Cat Using Her Litter Box? American Animal Hospital Association
Toxoplasmosis FAQs. Centers for Disease Control and Prevention