Why did my cat stop using the litter box? A step-by-step checklist

A cat that suddenly goes outside the box is one of the most stressful problems an owner can face. One person on X wrote this week: "This has been going on for a month. She won't use her own litter box." Cornell's Feline Health Center says house soiling is "the most common behavior problem reported by cat owners," and the ASPCA says at least 10% of all cats develop elimination problems. The sources agree on two things. Your cat isn't doing it out of spite, and the order you check things in matters. Here is that order, based on the pages we opened today.

Step 1: Rule out a medical problem first

Every source we read puts the vet visit first. The ASPCA says "the first step in resolving elimination outside the litter box is to rule out urine marking and medical problems," and Cornell warns that "cats with medical conditions may not always act sick."

Cornell lists the usual culprits. Urinary tract inflammation can make peeing painful and urgent. Kidney disease, thyroid disease and diabetes often make a cat drink and pee more. Digestive problems can make pooping painful or urgent. Age-related problems with mobility or thinking can stop a cat reaching the box in time. VCA adds colitis, constipation and anal sac disease for cats that poop outside the box, and notes that sore joints can make it hard to climb in or get into position.

Signs to mention to your vet (from the ASPCA and Cornell): going to the box often but producing only small amounts, straining, crying while peeing, blood in the urine, or licking the genital area a lot.

Emergency: Cornell says a cat that strains but passes little or no urine may have a urethral obstruction, which is "an absolute emergency, requiring immediate veterinary treatment." It notes that male cats are at greater risk. Don't wait to see if it passes.

One more thing to know. The ASPCA and VCA both say a cat that had pain while using the box can keep avoiding it even after the medical problem is treated, because it has learned to link the box with discomfort. So you may still need the steps below after the vet visit.

Step 2: Is it spraying or peeing?

Marking is a different problem with a different fix. Cornell and the ASPCA describe spraying as a cat standing up, tail raised and often quivering, and spraying small amounts of urine onto vertical surfaces like walls or the backs of chairs. A cat that marks usually still uses its box normally. Cornell says spraying is most common in unneutered males, but 10% of neutered males and 5% of neutered females also spray. Puddles on the floor, rugs or beds point to ordinary house soiling instead, which is what the rest of this page covers.

Step 3: Ask what changed around the time it started

VCA's first suggestion is simple: work out whether you changed the litter or the litter area around the time the problem began, and if so, switch back. The ASPCA lists other changes that can stress a cat enough to cause box problems: moving house, a new pet or family member, or even a change in your daily routine.

Step 4: Check the box itself

The ASPCA's list of common box problems is a good checklist:

• Not clean enough. Cornell says "some cats refuse to use a box containing any urine or feces whatsoever." The ASPCA says to scoop at least once a day. See our cleaning schedule.
• Not enough boxes. One per cat plus one (ASPCA, Cornell). See how many litter boxes you need.
• Too small. The ASPCA says most cats prefer large boxes and suggests plastic sweater storage containers. See our size guide.
• A hood or liner. The ASPCA says most cats don't like box liners or lids. Cornell says that from the cat's point of view "covers hold odors in." See covered vs open.
• Litter too deep. The ASPCA says cats usually prefer one to two inches, not three to four.
• Sides too high. Kittens, older cats and arthritic cats may struggle with high-sided or top-entry boxes. The ASPCA suggests a low-sided box.
• An old box. VCA says a box used for several years "may hold a residual odor," and suggests replacing it.
• A self-cleaning box. The ASPCA says many cats accept them, but if your cat starts going outside one, try a regular box. VCA notes some cats may fear the noise of the cleaning mechanism.

Step 5: Check the litter

The ASPCA says most cats prefer clumping, unscented litter with a medium to fine texture, and that a cat may prefer the type it used as a kitten. VCA says many cats dislike litter with strong deodorizers or perfumes. If you must change brands, Cornell says to do it gradually, mixing small amounts of the new litter into the old. The ASPCA's tip for finding out what your cat likes: put a few boxes side by side with different litters and see which one it uses. See scented vs unscented.

Step 6: Check the location

The ASPCA says to keep boxes away from busy, loud or intimidating places such as next to the washer and dryer, away from food bowls, and somewhere the cat won't feel trapped, with a box on each floor of a multistory home. VCA gives the example of a box in the far corner of a basement or near a furnace, and notes that older cats may not want to tackle the stairs. Our guide to where to put the litter box goes through this in detail.

Step 7: Look at the other animals in the house

The ASPCA says that in some homes one cat controls access to the boxes and keeps the others away, and that any conflict between cats can cause enough stress for box problems. Cornell asks whether another animal "terrorize[s] your cat while she's in the litter box or as she exits," and suggests an uncovered box with a 360-degree view, more than one way out, and several boxes in several places.

If you aren't sure which cat is having accidents, Cornell and VCA describe a few ways to find out. A video camera is the option VCA calls possibly "the best solution." Your vet can also give a non-toxic dye by mouth that shows up in urine under a black light, though VCA says results aren't always consistent and the dye may stain some carpets. For poop, both mention mixing a little chopped, non-toxic colored crayon into one cat's food.

What it means when your cat won't bury its poop

Another owner on X asked why their cat "never covers his shit in his litter box." Cornell lists refusing to bury waste alongside crying in the box, perching on the edge without touching the litter, and going right next to the box as signs a cat may dislike something about its setup. Its advice is to make sure the box is clean first, then look at the litter (especially after a sudden switch) and the box itself. None of the sources we read say an uncovered pile alone is a medical problem, but if it comes with any of the medical signs above, talk to your vet.

Stop the habit from setting in

Cornell says to act promptly: "The longer the behavior persists, the more likely it is to become a habit." The ASPCA explains that a cat that avoids its box can develop a lasting preference for another surface or spot, like a rug or a chair. Its suggestions while you work on the cause:

• Clean accidents with an enzymatic cleaner made to neutralize pet odors. See our guide to getting cat urine smell out of carpet and furniture.
• If your cat keeps using the same few spots, put a litter box there. If you can't, put food, water, a bed or toys there instead.
• Make favorite accident spots less appealing with a motion-activated light, an upside-down carpet runner, foil or double-sided sticky tape.

Cornell also suggests matching the litter to a surface your cat seems to prefer. For a cat that likes carpet, try a softer, finer litter with a carpet remnant in the box. If the box needs to end up somewhere else, move it "just a few inches a day."

When to get more help

VCA says that if a few simple changes haven't fixed things "after a couple of weeks," a more thorough look at the causes is needed. Cornell says anti-anxiety medication works better for spraying than for other house soiling, can only be "part of the solution," and must be monitored by a vet.

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