How to clean a cat litter box and keep the smell down

A cat judges a litter box by its own standards long before a person notices a smell. Cats avoid a dirty box, and a box they avoid leads to accidents on the carpet and the bed. A good routine keeps the box clean enough for the cat, keeps the smell from building up in the room, and makes the job quick.

Litter boxes can be cleaned without harsh chemicals. The main tools are a scoop, a bag, a bucket, mild soap and a little white vinegar. The most important rule is never to mix cleaners. This guide covers the daily scoop, the full change, the wash, the floor around the box, and the health problems that sometimes lie behind a smell.

The daily scoop

Scoop out clumps and solid waste once or twice a day. Use a scoop with fine slots, and tip the waste into a bag. Tie the bag and put it in an outdoor trash can or a sealed trash can. Replace the litter you removed, so the layer stays deep enough for the cat to dig.

Many cat owners find that a daily scoop does more for the smell than anything else. It is also the step most often skipped.

The full change

For clumping litter, empty the whole box every one to two weeks. Throw the old litter in a sealed bag. For non-clumping litter, change it weekly, because urine soaks into the granules and cannot be scooped out cleanly. Use the change as a moment to check the box. Look for wet patches, changes in the color or smell of the litter, or anything that does not look normal.

Pour in fresh litter to a depth the cat is comfortable with, usually two to three inches. Too little and the urine reaches the base. Too much and the cat may not dig.

How the calculator works

The litter amount calculator works out how much litter it takes to fill your box to the right depth. Enter the box’s length and width and the depth of the litter in inches. It gives the volume in US quarts and in liters.

Volume is length x width x depth in cubic inches. A US quart is 57.75 cubic inches and a liter is 61.024 cubic inches, so quarts = volume / 57.75 and liters = volume / 61.024. The default is an 18 by 15 inch box with 2.5 inches of litter: 18 x 15 x 2.5 = 675 cubic inches, which is 11.7 US quarts or 11.1 liters.

The default depth comes from the guide, which says to pour fresh litter to a depth the cat is comfortable with, usually two to three inches. The depth matters for a practical reason. Too little and the urine reaches the base of the box. Too much and the cat may not dig. The calculator accepts 1 to 6 inches and tells you in the working when your depth falls outside two to three inches.

It treats the box as a plain rectangle with straight sides, so a box with sloping or rounded sides holds a little less than the figure. It gives a volume, not a weight, and litter is often sold by weight, so check how much a bag holds before you buy. Use it for the full change, when you empty the whole box, which the guide puts at every one to two weeks for clumping litter. The daily scoop only replaces what you removed.

Washing the box

Empty the box, then wash it with hot water and mild, unscented dish soap. Scrub the corners and the base with a scrub brush or a sponge, because urine residue collects there and carries the smell. Rinse thoroughly, and dry the box fully before you add litter. A damp base encourages the bacteria that make the smell.

For a box with a stubborn smell, soak it in equal parts white vinegar and water for about thirty minutes, then scrub and rinse well. Vinegar cuts through urine residue, and the rinse removes the vinegar smell before the cat returns.

Do not use bleach on a box that has been used, unless you have rinsed it thoroughly first. Bleach can react with the ammonia in urine and create harmful fumes.

The floor and the wall around the box

Litter tracks onto the floor, and urine splashes onto the wall or the baseboards near the box. Sweep or vacuum the area around the box every day, and wipe the floor and the base of the wall once a week with a damp cloth. A mat under the box catches grains and makes sweeping easier.

Accidents need a different method. Use an enzyme cleaner made for pet urine, which breaks down the compounds that carry the smell. Ordinary cleaners often leave the smell behind, and a cat can detect it and return to the same spot. The guide on carpet and pet urine covers that process in more detail.

Odor and what it means

A box that still smells strongly after a clean may have a problem with the litter or the cat. Scented litter can make a cat avoid the box, so unscented litter is usually the safer choice. A strong smell of ammonia can mean the box is not cleaned often enough, or that the cat is urinating outside the box and the urine is soaking into the floor.

Keep the room ventilated, and use an air purifier near the box in a small room. A box placed in a small closed bathroom or a closet with no air movement will smell more than one in an open area, as long as it is not next to the cat’s food or water.

Choosing the litter

Litter comes as clumping clay, non-clumping clay, silica crystals, and plant-based pellets made from wood, paper, corn or wheat. Clumping clay makes it easy to remove waste and urine, and it lets you clean the box in patches, which is why many owners prefer it. Non-clumping litter needs the whole box changed more often, because urine is absorbed into the whole layer. Silica crystals hold odor well and need changing less often, but some cats dislike the texture. Plant-based pellets are lighter and produce less dust, and some can be composted or flushed where local rules allow it.

Dust matters for both the cat and the person. Low-dust litters are kinder to the lungs and make less mess on the floor. Scented litter is the most likely to put a cat off the box, so unscented litter is usually the better choice, even when a scent seems helpful to people. When you change the type of litter, mix the new one into the old over about a week, so the cat is not surprised by a sudden change underfoot.

Where to put the box

Place the box in a quiet spot, away from food and water bowls, and away from noisy machines such as washers and dryers. Cats do not like to eat near their toilet. A box that is hard to reach, such as one behind a door or in a cramped corner, can cause problems, especially for older cats or cats with arthritis.

Most homes need one box per cat, plus one extra. Spread the boxes around the house rather than clustering them in one room.

Signs of a health problem

Watch for changes in how the cat uses the box. A cat that goes often and produces little or no urine, that strains, that cries while peeing, or that starts going outside the box may have a urinary problem. A male cat that cannot urinate needs urgent veterinary care, because a blocked urinary tract can become fatal within a day or two. Any change in toilet habits should be checked by a vet, since changes in the box are often one of the first signs of illness in cats.

Also watch for diarrhea, blood in the stool or urine, and a change in how much the cat drinks. Call a vet for any of these signs.

Several cats

A home with more than one cat needs more care, because the boxes are used more and the smell builds faster. Keep one box per cat plus one, and spread them out. Scoop each box at least once a day, and check every box. A cat that is chased away from a box may avoid it and use another spot, so watch for a cat that waits at a box or moves between boxes repeatedly. That pattern can signal stress or a health concern.

Handling litter safely

Cat feces can carry a parasite called Toxoplasma gondii, which can seriously harm a developing baby if a pregnant woman is infected. If you are pregnant, ask someone else to change the litter. If you must do it, wear disposable gloves and wash your hands thoroughly afterward. Keep children away from the litter box. Wash your hands after cleaning the box, even if you wore gloves, and clean any tools you used. Do not flush litter unless the label says it is safe and local rules allow it.

Supplies to keep on hand

Keep a scoop, a stack of bags, a scrub brush, mild unscented soap, white vinegar and an enzyme cleaner for accidents. Store the cleaning products on a high shelf, out of the cat’s reach. Never mix cleaners, and rinse the box between products.