How to Get Rid of Cat Pee Smell: Step by Step for Every Surface

To get rid of cat pee smell, you have to remove the urine itself, because masking the smell does not last. Find every spot with a UV torch, blot up what you can, soak each spot with an enzyme cleaner well past the edges, and let it dry slowly without heat. Skip bleach, ammonia and steam. Then work out why your cat peed there, because a cat that keeps going back will keep the smell coming back too.

Why cat pee smells so strong

Cat urine is very concentrated, and several things in it smell. Understanding them explains why ordinary cleaning so often fails.

• Ammonia. Bacteria break down the urea in urine into ammonia. That is the sharp smell you notice first, and it gets stronger the longer the urine sits.
• Uric acid. This is the stubborn part. It forms crystals that do not dissolve in water or ordinary cleaners, and Hill's Pet Nutrition notes that it can stay in carpets, fabrics and wood for years. When the air is humid, the crystals pick up moisture and the smell returns. That is why a spot can seem fine for weeks and then smell again on a damp day.
• Felinine. A sulphur-containing compound found in the urine of cats. It has no smell when fresh, but its breakdown products give cat pee its typical "catty" odour. Research from Wageningen University and others shows that production depends on testosterone, and intact males excrete roughly three times as much as neutered males or females.

To neutralise the ammonia smell from cat urine for good, you have to remove the urine that keeps producing it. Airing the room and baking soda help with what is in the air, but as long as urine is left in the carpet or the floor, new ammonia keeps forming.

Does female cat pee smell as bad as male cat pee?

Usually not. The strongest smell comes from intact tom cats, because of the felinine and because they spray. A spayed female's urine smells much like a neutered male's. An unspayed female is a different story. According to the Cornell Feline Health Center, intact females are the second most likely group to spray, after intact males, and a female in season may mark around the house.

If your female cat's urine has a strong smell that is new, a different cleaner will not fix it. Concentrated urine is the most common reason. Cats that eat only dry food or drink little produce darker, stronger urine than cats on wet food. A urinary tract infection, kidney disease and diabetes can also change the smell. If the smell has changed and your cat is also peeing more often, straining, drinking more or behaving differently, see your vet and take a fresh urine sample with you if you can.

Step 1: find every spot with a UV torch

Cat urine glows under ultraviolet light. A UV torch, also called a black light, shows spots you cannot see and can no longer smell from standing height. This is often the difference between a room that stays fresh and one where the smell lingers, because people clean the puddle they found while the cat has used two other corners.

1. Wait until dark and close the curtains. The torch only works well in a fully dark room.
2. Hold it close to the floor and sweep slowly over carpets, skirting boards, the bottoms of curtains, the sides of the sofa and the walls near the litter tray. A cat that sprays leaves marks on vertical surfaces, roughly at tail height.
3. Urine shows up as a yellow-green glow, often as splashes or drip lines. Older stains glow more faintly.
4. Mark each spot with masking tape or chalk so you can find it in daylight.

A 365 nm torch usually shows urine more clearly than the cheaper 395 nm ones, which give off a lot of visible purple light. Not everything that glows is urine, as some detergents and spilled drinks light up too, so use your nose as a second check. On carpet, treat a bigger area than the glow, because urine spreads sideways once it reaches the underlay.

Step 2: the basic method for any surface

The method is the same everywhere. What changes per surface is how deep the urine went and how much liquid the material can take.

1. Blot gently. On a fresh puddle, press paper towels down until they come up almost dry. On carpet, stand on them. Rubbing pushes urine deeper and spreads it.
2. Test a hidden patch for colour loss before you use any cleaner.
3. Use plenty. The cleaner has to reach everywhere the urine went, so use plenty and go well beyond the edges of the stain.
4. Leave it to work. Follow the time on the bottle, usually 10 to 15 minutes for a fresh accident. For old stains, cover the spot with cling film or a plastic bag overnight so it stays wet and the enzymes keep working.
5. Blot the excess and let it dry slowly. The breakdown continues as it dries. No hairdryer, no heater, no steam.
6. Keep your cat off the spot until it is completely dry. An upside-down laundry basket or a sheet of foil works well.
7. Check again after a few days with the torch and your nose, and repeat where needed.

Do not worry if an old stain smells worse for a day after you wet it. That is common, and the smell usually fades as the cleaner works.

Which cleaner to use

Any good enzyme cleaner made for pet urine will do the job if you use enough of it and give it time. If you want to know which ones work best in the UK and US, and what owners say about them after real accidents, see our guide to the best cat urine odor eliminator, where we compare five enzyme cleaners side by side.

No enzyme cleaner in the house? Many UK vets and behaviourists use a cheap method with three spray bottles. The first holds biological washing powder or liquid in water, about 1 part to 10. The second holds plain water. The third holds clear surgical spirit, never coloured methylated spirit. Spray and wipe with the first bottle until nothing is left, rinse with the second, then finish with a light spray of the third and let it dry. Use paper towels throughout, because cloths spread the smell. Test it on a hidden patch first, especially on wallpaper and coloured fabrics.

Step 3: surface by surface

Carpet and rugs

1. Blot a fresh puddle until no more moisture comes up. For a dried stain, go straight to step 2.
2. Soak the spot and a margin around it of about twice its size, so the cleaner reaches the backing and the underlay.
3. For an old stain, cover it with plastic overnight.
4. Blot the excess and let the carpet air dry. Vacuum only once it is fully dry.
5. Check with the torch after a few days and treat again if it still glows or smells.

A rug that fits in the washing machine can go in on a cool wash with biological detergent (see laundry below). If a cat has used the same corner for months, the urine has probably reached the underlay and the floorboards. Surface cleaning cannot always reach that. Lift the carpet, check the underlay with the torch, replace the affected piece and treat or seal the boards before you lay it back. Never use a steam cleaner or a hot carpet shampooer on urine, because heat sets the stain.

Mattress

1. Strip the bed and wash the bedding separately.
2. Blot the mattress firmly with paper towels until they stay dry.
3. Soak the spot and the area around it with enzyme cleaner. In foam and springs, urine runs down and outwards.
4. Leave it for the time on the bottle, or overnight under plastic for an older stain, then blot again.
5. Let it dry completely, standing up near an open window or in front of a fan. Foam can take two or three days. If you need the bed before then, lay dry towels over the spot and change them every day.
6. Once it is dry, sprinkle baking soda over the area, leave it for a few hours and vacuum it up.

Put a waterproof mattress protector on afterwards. A cat that has peed on a bed once will often try again until the cause is sorted out.

Sofa and upholstery

1. Check the care label first. Removable covers can usually go in the wash. On fixed upholstery, a "W" code means water-based cleaners are fine, while "S" or "X" means water can leave marks and a professional cleaner is the safer choice.
2. Blot the surface, then soak both the fabric and the foam underneath. Urine almost always goes through to the filling.
3. If the cushion has a zip, take the foam out and treat it directly, then let it dry outside the cover.
4. Leave the cleaner to work, blot, and let it air dry. Keep the cat off the sofa until it is dry.

Leather, suede, silk, wool and velvet need extra care, and many enzyme cleaners are not made for them. Wipe leather with a damp cloth, use a cleaner made for leather, and always test first.

Hard floors: tiles, laminate and wood

1. Wipe up the urine with paper towels.
2. Spray enzyme cleaner over the spot and the joints around it. On hard floors, the smell hides in the gaps between boards and tiles.
3. Leave it for the time on the bottle, then wipe off with a damp cloth and dry the floor.
4. On laminate and wood, never let liquid stand. Water swells laminate edges and marks wood. Two thin applications are safer than one puddle.

Sealed tiles and sealed wood are the easy case. Old floorboards and unsealed wood soak urine up, and a stain that has turned dark may need sanding and resealing before the smell is gone. Skirting boards are worth checking too, especially if your cat sprays.

Tile grout

Grout is porous, so urine soaks in and the smell lingers long after the tile looks clean. This is common around a litter tray, where a cat may pee over the edge.

1. Scrub the grout lines with a soft brush and warm water first, then wipe dry.
2. Spray the grout generously with enzyme cleaner and lay a damp towel over it so the cleaner stays wet. Leave it for at least the time on the bottle, or longer for an old smell.
3. Wipe it off, rinse with clean water and let the grout dry completely, ideally for a day.
4. Once it is dry and smells clean, apply a grout sealer so new urine cannot soak in. Two thin coats work better than one.

Avoid bleach on grout. It does nothing against uric acid and can damage the grout. Be careful with vinegar too, because acid can wear down cement-based grout over time. If the grout was already sealed and still smells, the old sealer may need to come off before the cleaner can reach the urine. In bad cases, where urine has seeped under the tiles, regrouting is sometimes the only lasting fix.

Laundry, bedding and cat beds

1. Rinse the item in cold water first.
2. Wash it at a low temperature with a biological detergent, which contains its own enzymes. For a strong smell, add a capful of enzyme cleaner to the drum or soak the item in diluted cleaner for an hour beforehand.
3. Air dry it and smell it before it goes anywhere near the tumble dryer. Heat locks in any urine that is left.
4. Wash again if needed.

If your washing machine smells afterwards, run an empty hot wash. A cat bed or blanket that still smells after two washes is often easier to replace, because the cat will smell it long after you stop noticing it.

Walls, curtains and furniture legs

Vertical marks usually mean spraying. Wipe painted walls with the enzyme cleaner or the three-bottle vet method, using paper towels and keeping it wet for a few minutes. Test wallpaper on a hidden spot first. Curtains can usually go in the wash as above. Clean every marked spot on the same day, then check and clean again two or three days later, because a cat that sprays often tops up its marks.

What not to use, and why it backfires

• Bleach. It does nothing against uric acid, and the Missouri Poison Center warns that bleach mixed with cat urine can release chloramine gas, because urine contains ammonia. The effect is usually mild in a small spot, but there is no reason to take the risk.
• Ammonia-based cleaners. To a cat, ammonia smells like urine. Cornell advises against them because they can mark the spot as a toilet. Many glass and multi-surface cleaners contain ammonia, so check the label.
• Vinegar on its own. It can take the edge off the ammonia smell, but it does not break down the uric acid crystals that bring the smell back. Cornell also lists vinegar as a product to avoid, because it can smell like urine to cats and irritate them. If you have already used it, rinse with water before you apply an enzyme cleaner.
• Steam and heat. Steam cleaners, hairdryers and tumble dryers set the stain and the smell.
• Air fresheners and scented sprays. They cover the smell for you while your cat can still smell the urine underneath. Some can also stop an enzyme cleaner from working.
• Mixing products. Use one cleaner at a time and rinse in between. Several cleaners on the same spot rarely work better and can react with each other.

What about baking soda and hydrogen peroxide?

The popular home recipe of baking soda, vinegar, hydrogen peroxide and a drop of washing-up liquid can make a fresh spot smell much better. Even Hill's, which publishes a version of it, follows it with an enzyme cleaner after about 24 hours, because the uric acid will otherwise crystallise again and the smell returns. Hydrogen peroxide can also lighten carpets and fabrics, so test it on a hidden patch first and use only the weak 3% solution sold in chemists. Baking soda on its own is useful as a final step on a dry carpet or mattress to absorb leftover smell, but it does not remove urine.

When to see the vet

A cleaner deals with the smell. The reason your cat peed there needs attention too, and the first stop is your vet. Cornell calls house soiling the most common behaviour problem cat owners report, and points out that cats with medical conditions do not always act sick. Urinary tract inflammation, kidney disease, thyroid disease, diabetes and arthritis can all make a cat pee more often or avoid the tray.

Book an appointment if your cat:

• suddenly starts peeing outside the tray after years of using it
• goes to the tray often and passes only small amounts
• strains, cries or licks its genital area a lot after peeing
• has pink, red or brown urine
• pees on cool, smooth surfaces such as the bath, the sink or tiles
• drinks or pees much more than usual, or the urine suddenly smells much stronger

A cat that keeps going to the tray and produces nothing is an emergency. The PDSA warns that a blocked bladder is life-threatening and advises calling your vet immediately, day or night. Male cats are most at risk because their urethra is narrow.

Often the vet finds no infection and no stones. Then the diagnosis is frequently feline idiopathic cystitis, a bladder inflammation that the PDSA says is usually triggered by stress. A move, a new cat or baby, building work or tension between cats can set it off. If a new cat is the trigger, our guide on how to introduce cats explains how to slow things down.

Why your cat keeps going back to the same spot

Cats return to places that smell of urine, and a cat's nose is far better than yours. A spot that smells clean to you can still say "toilet" to your cat. That is one reason. The other is that whatever made your cat pee there in the first place has not changed yet.

Spraying or peeing?

Spraying is marking. The cat stands with its tail up, often quivering, and squirts a small amount of urine backwards onto a vertical surface such as a wall, a curtain or the side of the sofa. Peeing, squatting on a flat surface, points more often to a health problem or a problem with the litter tray. Neutering changes the smell of the urine and often reduces spraying, but Cornell notes that about 10% of neutered males and 5% of neutered females still spray. Spraying indoors is usually linked to stress, such as a cat outside the window, a new pet or changes at home. Clean every mark thoroughly and talk to your vet or a qualified behaviourist about the cause.

Make the spot less attractive

Cornell suggests a few simple ways to change what a spot means to your cat once it is clean and dry:

• Put food bowls or treats there, or play with your cat on that spot. Cats do not like to pee where they eat.
• Cover it for a few weeks with foil, plastic or a carpet runner turned nubs up.
• Block access by closing a door or moving a piece of furniture or a plant over the spot.

Never punish your cat. Shouting, or rubbing its nose in it, makes a cat more anxious, and anxiety makes house soiling worse.

Check the litter tray

Many cats stop using a tray they dislike. Cornell's basics are one tray per cat plus one extra, in quiet spots away from food, filled with unscented, fine litter about 2.5 to 5 cm deep, and scooped every day. Bigger cats need bigger trays, and older cats need low sides. Cornell also advises replacing trays that are cracked or smell, because a plastic tray absorbs odour over time. If your cat is leaving poo outside the tray as well, read why your cat poops outside the litter box.

If the whole house smells of cat pee

When there is no puddle to be found and the house still smells, the source is usually the litter tray or a spot you have not found yet.

• Scoop daily and clean the tray properly. Our complete guide to cleaning the litter box covers how often to change the litter and what to wash the tray with.
• Check the floor and walls around the tray with the UV torch. Urine over the edge of the tray soaks into grout and skirting boards.
• Do a full torch sweep of every room, including behind furniture and under beds.
• Air the house while you clean, and let treated spots dry with the windows open.

If daily scooping is hard to keep up with, an automatic litter box can help keep the tray clean between full changes. And if you want an early warning for urinary problems, health monitoring cat litter changes colour when something in the urine is off.

In severe cases, such as a house you have just moved into where a previous cat soiled for years, professional carpet cleaners and floor specialists can lift carpets, replace underlay and seal subfloors. Ask whether they use an enzyme treatment for pet urine, because a standard hot wash can set the smell.

Frequently asked questions