Litter Box Smell: How to Control It (Daily and Weekly Routine)

A litter box will always smell a little. But if you can smell it from the next room, or the smell has spread to the carpet and walls around it, something in the routine needs to change. The good news is that most litter box smell comes down to a few things you control: how often you scoop, the litter you use, how you wash the box, and where it sits.

This guide is based on litter tray advice from the RSPCA and the UK vet charity PDSA, and on the Cornell Feline Health Center. Getting it right matters for more than smell: PDSA points out that cats won’t use a dirty tray, and the RSPCA says a neglected tray can send a cat looking for somewhere else to go.

1. Scoop every day

The RSPCA advises spot cleaning the litter tray every day. Waste left in the box is the main source of smell, and a dirty box can also put a cat off using it. If you have more than one cat, or the box gets heavy use, scooping twice a day helps.

Tie the scooped waste in a bag and take it out of the house rather than leaving it in a bin next to the box.

2. Wash the box and change all the litter weekly

Scooping does not remove everything. The RSPCA says to replace all the litter at least once a week. That is also a good time to wash the box itself. In our view, warm water with a little unscented dish soap is enough, rinsed well and dried before you refill it.

1. Empty all the litter into a bag.
2. Wash the box with warm water and unscented soap or baking soda. Wear gloves.
3. Rinse well and dry the box completely.
4. Refill with fresh litter.

Plastic boxes get scratched over time, and scratches can hold odor. If a box still smells right after a proper wash, it may be time to replace it.

3. Choose the right litter, and the right amount

• Clumping and unscented. The RSPCA warns that strongly scented litter can put cats off their tray, so pick an unscented one. Clumping litter makes it easy to remove all the urine each day, which is what controls smell.
• Skip the scented litter. It may smell nice to you, but cats have a much stronger sense of smell, and a scent they dislike can put them off the box.
• Keep it shallow. The RSPCA says the litter should be deep enough for your cat to dig and cover, and that cats differ in how deep they like it. In our view, one to two inches suits most cats and is easier to keep fresh than a very deep layer.
• Change brands slowly if you switch, so your cat gets used to it.

4. Enough boxes, big enough

• One per cat, plus one. The RSPCA recommends one tray per cat, plus a spare. Fewer boxes mean each one gets dirty faster.
• Size matters. The RSPCA says a tray should be big enough for your cat to get in easily and turn around.
• Lids and liners. PDSA and the RSPCA say cats differ: some like a covered tray, others prefer an open one. If you try a lid, keep an open box available too. A lid can trap the smell inside for your cat, even if it hides it from you.

5. Put the box in the right place

The RSPCA advises a quiet area of the house, because cats prefer privacy. In our view, a spot where your cat can see around it and leave easily works best. A spot with a little airflow also helps smell clear. PDSA says to keep trays away from your cat’s food and water. In a home with more than one floor, put a box on each floor.

6. Clean the area around the box

If the room smells even when the box is clean, check around it. Cats sometimes miss the box, kick out wet litter, or go just outside it. Use a UV black light in a dark room to check the floor, the wall behind the box and any nearby carpet. Our black light guide explains how.

• A washable mat under the box catches litter and small spills.
• Treat any urine you find with a pet odor product, following the label. Cornell says odors must be neutralized, not just deodorized to escape a cat’s keen sense of smell.
• Avoid ammonia and vinegar near the box. Cornell advises against them because they smell like urine and can be irritating.

For spots on carpet, see our cat urine guide.

Litter scattered across the floor? See how to stop cat litter tracking and clean up around the box.

For a ferret’s litter tray, which needs a different routine and litter, see how to clean a ferret cage, litter tray and hammocks.

What does not help

• Air fresheners and scented sprays near the box. They cover the smell for you, and a strong scent near the box can put your cat off it. Scooping and washing are what actually remove the smell.
• Strong-smelling cleaners. The RSPCA warns that strong scents from cleaners can put your cat off its tray, and says to use only cat-safe products.
• Adding more litter instead of changing it. Deeper litter does not absorb smell better, and most cats prefer it shallow.

When the smell is a warning sign

Talk to your veterinarian if the smell of your cat’s urine changes suddenly, if your cat is going much more or less often, or if they start going outside the box. The RSPCA says regular accidents indoors are a reason to see your vet, because they can have a health cause. If your cat is peeing on walls or furniture rather than the floor, that may be marking; see our guide to cat spraying.

Using an automatic box? See how to clean a self-cleaning litter box for the waste drawer, sensors and base.

A simple routine

• Daily: scoop each box, take the waste outside, sweep up loose litter.
• Weekly: empty, wash with unscented soap or baking soda, dry, refill with fresh unscented litter.
• Monthly: check around each box with a black light and treat any spots.

For accidents around the box, our Pet Cleanup Kit includes gloves, an absorbent powder, a stain and odor foam, a brush and a black light.

Frequently asked questions

How often should I change cat litter?

The RSPCA advises spot cleaning every day and replacing all the litter at least once a week, when you wash the box.

What is the best litter for smell?

Use an unscented litter, since the RSPCA says strong scents can put cats off. Clumping litter lets you remove all the urine every day, which is what keeps smell down.

Do covered litter boxes reduce smell?

They can hide it from you, but they also hold it inside for your cat. PDSA and the RSPCA say some cats like a covered tray and others do not, so watch how yours reacts.

Why does my house smell like cat pee even though the box is clean?

Usually because of urine outside the box: on the floor beside it, the wall behind it, or elsewhere in the home. Check with a black light and treat any spots you find. If your cat has started going outside the box, see your veterinarian.

Sources

• RSPCA: How to train a cat to use a litter tray
• PDSA: How to litter train your cat
• Cornell Feline Health Center: Feline behavior problems: house soiling

This guide is general information. Talk to your veterinarian about any change in your cat’s litter box habits.