How to Get Rid of Cat Litter Box Smell

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How to get rid of cat litter box smell: scoop solid waste at least once a day, replace all the litter and wash the box about once a week, use unscented litter and mild cleaners, and clean accidents with an enzymatic cleanser. The ASPCA and the Ontario SPCA both describe this routine, and both warn against strong scents near the box. Odor usually builds up from waste left in the box, so routine cleaning does most of the work. This guide explains the steps, the sources behind them and what the sources do not settle.

Quick answer

Scoop solid waste at least once a day, and twice if you can.
Replace all the litter and wash the box about once a week with warm water and unscented soap, baking soda or nothing.
Avoid ammonia, deodorizers and scented cleaners, because cats can dislike strong smells.
Use unscented, clumping litter in a shallow layer, and an uncovered box with low sides.
Clean accidents with an enzymatic cleaner, and see a vet if odor or soiling changes suddenly.

Scoop every day

The ASPCA’s litter box problems page says virtually all cats like clean boxes and advises scooping and changing litter at least once a day. The Ontario SPCA’s odor advice goes further: scoop solids at least once daily, twice if possible, and dispose of them outside the home. Daily scooping prevents waste from soaking into the litter and building a smell that spreads through the room.

General guidance: keep a small scoop and a sealed bag near the box so the habit takes less effort.

Replace the litter and wash the box weekly

Both the ASPCA and the Ontario SPCA recommend a full cleaning about once a week. The ASPCA says to rinse the box with baking soda or unscented soap once a week and completely replace the litter. The Ontario SPCA says to wash the box with mild soap and hot water rather than harsh chemicals. The Ontario SPCA also notes that you should change litter sooner if you notice odors or wet, clumped areas.

General guidance: dry the box fully before adding new litter, so the bottom does not stay damp and smelly.

Avoid scented products

The ASPCA warns that scented cleaners can cause a cat to develop an aversion to the smell, and it lists ammonia and strong scents as problems. Humane World advises avoiding strong scents and air fresheners near the litter box. The ASPCA also says most cats prefer clumping, unscented litter.

The Ontario SPCA’s odor article says that many cats dislike covered boxes, because odors are trapped inside and the cat has less visibility. An uncovered box with low sides is the option the sources favor.

Choose the right litter

The ASPCA says most cats prefer clumping, unscented litter with a medium to fine texture, and usually one to two inches deep rather than a deep layer. The ASPCA also notes that cats may have a litter preference formed as kittens. If you change litter, offer the new one next to the old one so the cat can show its preference.

The Humane World guidance on litter training adds that scented litter can be overwhelming for cats, and it suggests a light layer of baking soda at the bottom of the box as a way to control odor without deterring the cat. For more on choosing, see types of cat litter and scoopable cat litter.

Clean accidents with an enzymatic cleaner

The ASPCA recommends cleaning accidents thoroughly with an enzymatic cleanser designed to neutralize pet odors, which you can find at most pet stores. A regular cleaner may leave an odor that draws the cat back to the same spot. If the cat repeatedly soils the same place, the ASPCA advises making the area less appealing and placing a litter box there.

General guidance: test a cleaner on a small hidden area of fabric or wood before you use it on a larger one.

Add boxes in multi-cat homes

The ASPCA and Humane World both state the common rule of one litter box per cat, plus one extra. The ASPCA adds that a multi-level home may need a box on each floor. An overcrowded box fills faster and smells more, so extra boxes can reduce odor as well as avoid conflict. For a larger household, see best cat box for multiple cats.

Odor absorbers and air

The Ontario SPCA suggests a thin layer of baking soda in the bottom of the box. Humane World recommends keeping air fresheners away from the box. General guidance: place the box in a room with airflow rather than in a small closed space, and do not rely on odor absorbers alone. They help, but they do not replace scooping and cleaning.

When odor points to a health problem

The ASPCA says a cat that frequently enters the box but passes only small amounts of urine may have a urinary tract infection and should see a vet. The Ontario SPCA’s out-of-box article says to take a cat to the vet to rule out health problems such as urinary tract infections, so a vet visit is worth considering if odor or soiling changes suddenly.

How we chose

We limited this guide to the ASPCA, Cornell, Humane World and Ontario SPCA pages we opened on 2026-10-27. We kept the advice those pages state directly and marked the rest as general guidance.

What we could not verify

The sources do not name a single cleaning product as the best option, so this guide names none.
The sources do not say how long a box can be used before it should be replaced.
We did not find a source that measures how much a given litter reduces odor.
The sources do not say how often to change litter in a multi-cat home.

FAQ

How often should I scoop?

At least once a day, and twice if possible, according to the Ontario SPCA and the ASPCA.

How often should I wash the box?

About once a week, with warm water and unscented soap, baking soda or no soap, as the ASPCA advises.

Is bleach safe to use?

The sources do not recommend harsh chemicals. The ASPCA warns against ammonia and scented cleaners. Ask a vet or the product maker before using bleach near a cat.

Does baking soda help?

The Ontario SPCA suggests a thin layer in the bottom of the box. It is a common odor aid, but it does not replace scooping and weekly cleaning.

Should I buy a covered box to hide the smell?

The sources generally advise against covered boxes, because odor can get trapped inside and cats may dislike the enclosure.

When should I see a vet?

If the cat strains, produces small amounts of urine, or the odor and soiling change suddenly, contact a vet.

Bottom line

Cat litter box smell comes mostly from waste left in the box and from strong scents, so the fix is routine: scoop daily, change the litter and wash the box weekly, use unscented litter, and clean accidents with an enzymatic cleaner. Sudden changes in urination or odor are a reason to ask a vet.

Sources

ASPCA, Litter Box Problems: https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/litter-box-problems (opened 2026-10-27)
Ontario SPCA and Humane Society, Five tips to combat smelly kitty litter: https://ontariospca.ca/blog/five-tips-to-combat-smelly-kitty-litter/ (opened 2026-10-27)
Ontario SPCA and Humane Society, Litter box best practices: https://ontariospca.ca/blog/litter-box-best-practices/ (opened 2026-10-27)
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 2026-10-27)
Humane World for Animals, How to Litter Train a Kitten or Cat: https://www.humaneworld.org/en/resources/how-litter-train-kitten-or-cat (opened 2026-10-27)