When a Cat Stops Using the Litter Box

Q: Should I see a vet before I change anything?

Yes. Cornell says cats with these problems should be checked by a veterinarian, and the ASPCA page says to have the cat checked thoroughly by a veterinarian.

Q: How many litter boxes does my home need?

Cornell says to keep as many litter boxes as cats in the house, plus one. A home with two cats would have three boxes.

As an Amazon Associate we earn from qualifying purchases. Details

Short answer: When a cat doesn’t use litter box as it did before, start with a vet check. Cornell says cats who are having problems using the litter box consistently should be checked by a veterinarian. The pages we opened cannot name the cause for any one cat.

The person typing “cat doesn’t use litter box” wants to know why the cat stopped and what to change first. We opened three Cornell and ASPCA pages and checked each quote against the page text. They agree that medical causes come first.

Quick answer

Cornell says: “Cats who are having problems using the litter box consistently should be checked by a veterinarian.”
The ASPCA page says: “The first step in resolving elimination outside the litter box is to rule out urine marking and medical problems. Have your cat checked thoroughly by a veterinarian.”
Cornell lists the causes: “medical problems, an aversion to the litter box, or a preference for urinating or defecating in places outside the box.”
Cornell gives a count: “Keep as many litter boxes as cats in the house – plus one.”

Start with a vet check

Cornell’s house soiling page says: “Once you have identified the house-soiling cat, it is wise to take him to your veterinarian for a thorough physical examination and appropriate diagnostic tests to check for underlying medical problems.” It also says: “Cats with medical conditions may not always act sick.” That is why the page puts medical causes first: “Once medical causes have been ruled out, your detective work begins.”

Check the box, the litter and the count

If the vet finds no medical cause, the box is the next place to look. Cornell says: “Some cats refuse to use a box containing any urine or feces whatsoever.” It also says: “Replace old boxes that smell or are cracked.” Cornell says: “Larger cats need bigger boxes, and kittens and elderly cats need boxes with low sides.”

Covers are a common question. Cornell says: “Although humans like covered boxes for reducing odor and stray litter, from your cat’s point of view, covers hold odors in.” The ASPCA page says: “Remove covers and liners from all litter boxes.”

For litter, Cornell says: “Most cats prefer unscented, finer-textured litter about one to two inches deep.” If you must change it, Cornell says: “If you must switch brands, do so gradually.” It adds that “You may need to purchase several types of boxes and several types of litter to determine which combination your cat likes best.”

Location and moving the box

Cornell says: “Most cats prefer a location that is quiet, private, separate from their feeding area, and easily accessible 24 hours a day.” The ASPCA page says to place litter boxes “in accessible locations, away from high-traffic areas and away from areas where the cat might feel trapped.” If you have more than one floor, the ASPCA page says “you may need to provide a litter box on each level.” Cornell adds: “Do not locate the litter box upstairs or downstairs if your cat has trouble climbing stairs.”

If the cat has a favorite spot, Cornell suggests placing a box there first. It says: “Once she reliably uses it, gradually move the box just a few inches a day back to the desired location.” It also says: “Stop moving the box if she stops using it.”

What each source says

The table lists only what each page says. “Not stated” means the page does not address that point.

Point	Cornell house soiling page	Cornell Choosing and Caring page	ASPCA Litter Box Problems page
Vet check	“should be checked by a veterinarian”	Not stated for litter problems	“Have your cat checked thoroughly by a veterinarian.”
Number of boxes	“Keep as many litter boxes as cats in the house – plus one.”	“Provide as many boxes as you have cats, plus one.”	Not stated as a count. For cats in conflict: “provide additional litter boxes in locations where the anxious cat spends the majority of her time”
Box size or sides	“Larger cats need bigger boxes, and kittens and elderly cats need boxes with low sides.”	“kittens and elderly cats suffering from arthritis may need a box with sides that are low enough for them to enter easily”	“Try switching to a litter box with low sides.”
Covers	“covers hold odors in” (from the cat’s point of view)	Not stated	“Remove covers and liners from all litter boxes.”
Litter	“Most cats prefer unscented, finer-textured litter about one to two inches deep.”	“Most, but not all, cats prefer unscented, fine-textured litter.”	“Cats generally prefer clumping litter with a medium to fine texture. Use unscented litter.”
Food and water	“Cats prefer to eat and eliminate in separate areas”	“separate food and water dishes, kept far away from the litter box”	“Put your cat’s food bowls somewhere other than right next to her litter box.”
Location	“quiet, private, separate from their feeding area, and easily accessible 24 hours a day”	Not stated	“away from high-traffic areas and away from areas where the cat might feel trapped”
Cleaning	“Replace old boxes that smell or are cracked.”	“Cats may avoid a litter-box area that isn’t clean.”	“Do not clean up accidents with an ammonia-based cleanser.”

How we chose

On 2026-10-19 we opened three pages: Cornell’s house soiling page, Cornell’s Choosing and Caring for Your New Cat page, and the ASPCA Litter Box Problems page. We checked each quote against the text of the page. We did not name or rank any product in this post.

What we could not verify

The pages do not say which cause applies to your cat. Cornell says: “Once medical causes have been ruled out, your detective work begins.”
They do not give a box size, a height, or a distance from a wall or a dish.
They do not say how long a cat takes to use a box again after a change.
They do not say whether a particular box or litter brand suits any cat.

Buying checklist

Book a vet check before you change the box. Cornell says a cat with these problems should be checked by a veterinarian.
Count the cats and add one box.
Choose an uncovered box, with low sides for a kitten or an older cat.
Use unscented litter about one to two inches deep, as Cornell describes.
Place the box away from food and water dishes, in a quiet and accessible spot.

Mistakes to avoid

Skipping the vet. Cornell says cats with these problems “should be checked by a veterinarian.”
Buying a covered box for odor. Cornell says covers hold odors in, from the cat’s point of view.
Switching litter all at once. Cornell says: “If you must switch brands, do so gradually.”
Using a scented cleaner on accidents. The ASPCA page says: “The problem with scented cleaners is that your cat could develop an aversion to the scent.”

FAQ

Why did my cat stop using the litter box?

Cornell lists medical problems, an aversion to the box or litter, and a preference for another spot. The pages we opened do not say which one applies to your cat.

Should I see a vet before I change anything?

Yes, according to both pages. Cornell says cats with these problems should be checked by a veterinarian, and the ASPCA page says: “Have your cat checked thoroughly by a veterinarian.”

How many litter boxes does my home need?

Cornell says to “Keep as many litter boxes as cats in the house – plus one.” A home with two cats would have three boxes.

Can I move the box to a new spot?

Cornell says to place a box in the spot the cat prefers, then move it “just a few inches a day” once she uses it reliably. Stop moving it if she stops using it.

Is a covered box a bad idea?

Cornell says most cats prefer an uncovered box that lets odors escape. The ASPCA page says to remove covers from all litter boxes.

Bottom line

Get a vet check before anything else. Then work through the count, the box, the litter and the location. If you must move the box, move it a few inches a day, as Cornell describes. The pages we opened cannot name the cause for your cat.

For room planning, see our guide to litter boxes for small apartments. If you want less daily cleaning, see our guide to self-cleaning litter boxes and our Litter-Robot 4 review. The ASPCA page says that if a cat starts eliminating outside a self-cleaning box, you should try a traditional box. For vertical resting spots, see our guides to cat trees for small apartments and cat window perches. For food and water away from the box, see automatic cat feeders and cat water fountains. For play away from the box, see interactive toys for indoor cats.

Sources

Cornell Feline Health Center, Feline Behavior Problems: House Soiling: https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-behavior-problems-house-soiling (opened 2026-10-19). Cited for the vet check, causes, box count, box sides, covers, litter, location, and moving the box.
Cornell Feline Health Center, Choosing and Caring for Your New Cat: https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/choosing-and-caring-your-new-cat (opened 2026-10-19). Cited for the box count, separate food and water dishes, litter and cleaning.
ASPCA, Litter Box Problems: https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/litter-box-problems (opened 2026-10-19). Cited for the vet check, covers, box sides, placement, food bowls, cleaning, and scented cleaners.

Disclosure: As an Amazon Associate we earn from qualifying purchases. This page is for information only. Check the current price on Amazon. Read our affiliate disclosure.