How to Get Rid of Cat Urine Smell: What Really Works

If your cat has been peeing on things around your home or in your car (the couch, armchairs, shoes, carpets), leaving behind stains and that unmistakable smell, this article is for you. We’ll explain why cat urine smells so strong, how to get rid of the smell at home, which products really work and how to stop it from happening again.

First things first: if your cat has suddenly started peeing outside the litter box, take it to the vet. Urinary tract problems, bladder inflammation, kidney disease and diabetes are common causes. If your cat, especially a male, is straining in the litter box and producing little or no urine, it’s an emergency. Read more: why your cat has stopped using the litter box.

Why Does Cat Urine Smell So Bad?

Cat urine is highly concentrated, and its smell gets worse over time:

• Urochrome is the pigment that gives urine its yellow color and causes stains.
• Urea is broken down by bacteria into ammonia, which causes the sharp smell of an old accident.
• Uric acid forms crystals that don’t dissolve in water. That’s why the smell comes back, especially on humid days, even after you’ve washed the area.
• Unneutered male cats’ urine also contains a compound called felinine, which gives it a particularly strong, “tomcat” odor.

When you wash a stain with ordinary soap and water, you remove the first two components, but the uric acid crystals stay behind. That’s why the smell returns after a while. Porous surfaces that soak up moisture, such as carpets, mattresses, upholstery and unsealed wood, are the hardest to clean.

Tip: Can’t find the spot? Turn off the lights and use an inexpensive UV (black light) flashlight. Dried cat urine glows yellow-green under UV light.

How to Get Rid of Cat Urine Smell

The golden rule: act fast. A fresh accident is much easier to deal with than an old one.

1. Blot up as much urine as you can with paper towels or an old towel. Press firmly; don’t rub, as rubbing spreads the urine deeper.
2. Rinse the area with a little cool water and blot again. Don’t use hot water or a steam cleaner, since heat can “set” the stain and the smell into the fibers.
3. Treat the spot with an enzyme cleaner (see below) and let it work.
4. Let the area air-dry completely. Keep your cat away from it until it does.

Important: Always test any cleaner on a small, hidden area first, to make sure it doesn’t discolor or damage the surface.

Enzyme Cleaners: the Most Effective Option

Enzyme (bio-enzymatic) cleaners contain enzymes and “friendly” bacteria that break down the uric acid crystals and other components of urine, eliminating the smell at its source instead of masking it. This is important, because if your cat can still smell its urine, even when you can’t, it will keep coming back to the same spot.

Popular enzyme cleaners include Nature’s Miracle, Rocco & Roxie Professional Strength, Simple Solution and Urine Off. They cost about $10–25 / £8–20 a bottle. For best results:

• soak the area thoroughly, so the cleaner reaches as deep as the urine did, including the carpet pad or mattress filling;
• leave it to work for the time on the label, often 10 to 15 minutes or longer, and cover it loosely with a towel or plastic sheet to keep it from drying too quickly;
• let it dry naturally, and repeat if the smell lingers;
• don’t use other cleaners or disinfectants at the same time, as they can kill the enzymes.

In the UK, a popular budget trick is to use a solution of biological laundry detergent (the kind with enzymes) and warm water, followed by a rinse with water. Test it on a hidden spot first.

Home Remedies

If you’ve been caught off guard and don’t have an enzyme cleaner on hand, you can use household items. They can help with fresh stains, but they don’t break down uric acid as well as enzyme cleaners.

• White vinegar. Mix one part vinegar with one part water, spray or blot it onto the stain, leave it for a few minutes and blot it dry. Vinegar neutralizes the ammonia smell. Don’t use it on natural stone or waxed wood.
• Baking soda. After the area is almost dry, sprinkle it generously with baking soda, leave it overnight to absorb odors and vacuum it up.
• Baking soda, hydrogen peroxide and dish soap. Mix about 1/2 cup (120 ml) of 3% hydrogen peroxide with 1 teaspoon of baking soda and a squirt of dish soap. Apply it to the stain, leave it for 15 to 30 minutes, blot and rinse. Mix it fresh each time, and don’t store it in a closed container. Hydrogen peroxide can bleach fabrics and carpets, so always test it first.
• Laundry. For washable items like clothes, blankets and cushion covers, rinse in cold water, then wash with an enzyme laundry detergent, or add a cup of vinegar or an enzyme laundry additive to the wash. Air-dry and check the smell before putting items in a hot dryer.

For old, deep-set smells, you may need to combine several methods and repeat them. Sometimes the urine has soaked so deep that the only solution is professional carpet or upholstery cleaning, or replacing the carpet pad.

What Not to Use

• Ammonia-based cleaners. Ammonia smells like urine to a cat and may encourage it to pee in the same place again.
• Bleach and other chlorine-based cleaners. They don’t remove the smell, can damage surfaces and are irritating to people and pets. Mixing bleach with urine, which contains ammonia, or with vinegar can release toxic gases.
• Essential oils and strong fragrances. Many essential oils are toxic to cats, and air fresheners only mask the smell.
• Steam cleaners or hot water on fresh urine, which can set the smell permanently.

Read more: how to litter train a kitten and why your cat is peeing everywhere.

How to Remove Cat Urine from Different Surfaces

Be careful when removing stains, and always test the cleaner on a hidden area first.

Upholstered furniture. Blot as much urine as possible, then saturate the area with an enzyme cleaner. If the urine has soaked into the cushion, remove the cover and wash it separately, and treat the foam inside. For leather, use a gentle leather cleaner or a little diluted vinegar, and finish with a leather conditioner.

Hard floors. On tile, vinyl, sealed hardwood or laminate, wipe up the urine, clean with an enzyme cleaner or a solution of equal parts vinegar and water, and dry thoroughly. Don’t leave liquid standing on laminate or wood. If urine has soaked into unsealed wood or the gaps between boards, the wood may need to be sanded and resealed.

Mattresses. Blot thoroughly, then saturate the spot with an enzyme cleaner and let it dry completely, ideally in the sun or with a fan. Sprinkle with baking soda once dry, leave it for several hours and vacuum. A waterproof mattress protector will save you a lot of trouble in the future.

Shoes. Shoes are tricky. If you catch the “crime” right away, your chances of saving them are much better. Stuff the shoes with paper towels or newspaper to soak up the moisture, then wash them: many sneakers can go in the washing machine with an enzyme detergent. For leather shoes, wipe the inside with an enzyme cleaner and let them dry naturally. If nothing helps, unfortunately, the shoes may have to go.

Carpets. For fresh stains, blot thoroughly, rinse with a little water, blot again and treat with an enzyme cleaner, soaking it into the padding. For old stains, use an enzyme cleaner and repeat several times, or rent or hire a carpet cleaner, using it with cool water and a pet-urine formula.

Car seats. Blot the area immediately, then treat with an enzyme cleaner suitable for car upholstery, or a leather cleaner for leather seats. Always take your cat to the vet in a secure carrier lined with a puppy pad or towel to avoid accidents.

How to Prevent Accidents

To stop the problem from happening again and again, follow these tips:

1. Have your cat checked by a vet to rule out medical problems. Many owners discover that a sudden strong ammonia smell from the litter box or accidents around the house were caused by a bladder infection or inflammation, and the problem disappeared once it was treated.
2. Spay or neuter your cat. This is the most effective way to prevent urine marking: it reduces spraying in most cats and makes urine smell much less strong.
3. Make the litter box as appealing as possible: one box per cat plus one extra, in quiet, easy-to-reach places, scooped at least once a day, with an unscented, clumping litter most cats prefer.
4. Clean every accident spot thoroughly with an enzyme cleaner, so your cat doesn’t smell it and return.
5. Make the spots your cat has soiled less appealing: put a food bowl, toys or a bed there (cats don’t like to pee where they eat or sleep), cover the area temporarily with foil or plastic, or use a cat-safe deterrent spray. Read about scents that repel cats.
6. Reduce stress. Changes at home, new pets or cats outside the window can trigger marking. A synthetic pheromone diffuser, such as Feliway, can help. Read more: how to calm a stressed cat.