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How to Remove Old Urine Stains from Carpet Effectively

How to remove old urine stains from carpet

Some carpet stains are easy to forget, but urine certainly isn’t one of them. Whether fresh or months old, pet urine stains stay resilient as ever, making the carpet look terrible and the room smell awful unless you eliminate the source. Until then, you can forget about entertaining in that part of the house at least.

Easier said than done, cleaning cat and dog urine stains can be quite an aggravation if you let them soak in and dry. Deodorizers might offer some relief, but the pee smell will undoubtedly return. Learn the best ways to kill the problem for good as I explain everything you need to know about how to remove old urine stains from carpet.

How Do You Identify an Old Urine Stain?

The darkened patch of liquid soaking into the carpet makes fresh pet stains relatively easy to spot. But how do you find those that have had a chance to dry and blend with the surrounding material? While you don’t have any trouble smelling the pee, pinpointing the precise location is far from easy without the proper tools.

UV Flashlight

Unless you want to get down on your hands and knees to sniff out the urine’s location, a minor investment in a UV flashlight is your best bet to find the pet stain. An inexpensive direct light like the Escolie UV flashlight can pick up old urine, as the phosphorus content will glow a yellowish hue.

Moisture Meters

Moisture probes are often the most accurate tools for finding urine. Uric acid crystals continually attract moisture, providing barely enough dampness to register on these meters and cause an ongoing dog or cat smell even several months after the incident.

Moisture meters can pick up readings in areas where blacklights might not show a stain, and you won’t get false positives from other marks (bodily fluids) that might glow under UV. The primary issue is cost. Professional moisture detectors can run a few hundred dollars, which may not be practical for homeowners dealing with infrequent pet accidents. You might have some luck with a standard wood moisture meter, but it won’t be as reliable with old stains.

How To Treat Old Pet Urine Stains

My Recommendation: Enzyme Cleaner

An enzyme cleaner will give you the best results with a urine stain that is dried and absorbed into the carpet. Live bacteria and enzymes in these cleaners accelerate the breakdown of the smell-producing urea components, converting them to water and CO2 for them to harmlessly evaporate. Popular products to try include:

Many products have a recommended dwell time of 5–60 minutes, but you can leave them for several hours for more intense staining. If left to sit, a stain will soak into the carpet padding and potentially the subfloor. The urine will often spread wider than what is visible on the carpet’s surface, a critical consideration when applying your cleaning solution. 

How To Clean Urine Stains in Carpet With Enzyme Cleaners

  1. Liberally spray the enzyme cleaner over the stain, going beyond the edges to ensure it reaches all the underlying urine
  2. Let the cleaner sit for the recommended dwell time, leaving it for up to 8 hours if the staining is severe
  3. Soak up any remaining liquid with clean towels or paper towels, putting a weight on them to absorb water deep in the carpet
  4. After absorbing all the liquid, rinse the area with plain tap water and a damp cloth to remove lingering residue
  5. Absorb the water with towels or a wet/dry vac until the area is completely dry

Note: Enzyme cleaners can destroy pet urine smell better than most cleaners, but they don’t always do a spectacular job on discoloration. To make urine marks vanish, I recommend a carpet spotter, like the Bissell Little Green portable carpet cleaner with a quality pet stain remover. Alternatively, a carpet cleaning spray like Resolve Carpet & Rug can handle any remaining staining to make your carpet look new.

Hydrogen Peroxide

Hydrogen peroxide is one of the best DIY solutions for eliminating challenging colorful messes like spilled red wine or a deep-set yellow stain from urine. It’s typically better than an enzyme cleaner at restoring the look of your carpet. The peroxide lightens discoloration as it oxidizes the staining compounds. Additions like baking soda and dish soap supply extra soil-lifting and deodorizing power. Here’s how to use them in a spray to remove urine stains:

  1. Pour one cup of hydrogen peroxide into a spray bottle with a couple of drops of dish liquid and 2–3 tablespoons of baking soda
  2. Mix well until the baking soda dissolves
  3. Spot test in an inconspicuous spot on the carpet, letting it dry to ensure it doesn’t leave any discoloration
  4. Shake the solution, and spray the stain liberally, going a little beyond the edges of the stain
  5. Scrub the solution gently into the carpet, and leave it to sit for 20–60 minutes
  6. Rinse the area with a damp cloth to remove the leftover cleaning solution
  7. Blot dry with paper towels or soak up excess moisture with a wet/dry vac

Note: Like our solution for cleaning cat urine from wood, a more powerful hydrogen peroxide product can speed up the stain removal process and improve results. An upgrade to a 20-volume clear developer if your standard 3% peroxide isn’t removing urine stains effectively enough. Spot testing is critical when using a more potent solution, so you can dial in the exact timing and technique to prevent damage. 

How To Clean a Fresh Urine Stain

Hopefully, you’ll get to the stain while it’s still damp. In this instance, your first move should always be to blot the area to remove as much urine as possible. A wet/dry vac is a huge asset in these situations. Before applying a cleaning solution, you can flush the stain with cold water and extract the liquid immediately with the vacuum, pulling even more urine out of the carpet.

After drying the spot, try one of these methods to clean the urine and prevent nasty stains from setting.

My Recommendation: Vinegar and Baking Soda

Combining their deodorizing and stain-lifting powers, vinegar and baking soda can be effective against fresh pet urine stains. After blotting up as much urine as possible with a dry cloth or paper towels, follow these steps to flush the spot and finish the job:

  1. Mix distilled white vinegar and warm water in a 1:1 ratio in a spray bottle
  2. Shake the solution, and spray the stain liberally
  3. Gently scrub the solution into the spot
  4. Blot as much moisture as possible with a clean cloth
  5. Sprinkle baking soda in a generous layer over the stain to absorb any remaining urine or cleaner, leaving it for a few hours
  6. Once dry, vacuum the baking soda

Note: Vinegar makes a decent deodorizer and cleaner for a fresh urine stain, but it isn’t powerful enough to dissolve all the crystalline compounds that bind pee to the carpet and cause the smell. You may notice an odor a few days after the vinegar treatment. In this situation, take the quickest and most straightforward route by upgrading to an enzyme cleaner.

Soap and Water

Dish soap in water has always been one of my top options for quickly dealing with a fresh stain like dog urine. The soap suspends the stain-causing components to let you blot or vacuum away the liquid. Here’s how you can use it to get recent wet stains out of carpet in only a few minutes:

  1. Add 1–2 drops of dishwashing liquid in a bowl of warm water
  2. Dip a clean rag or sponge in the soapy solution, and blot the stain
  3. Rinse the soap from the spot with a cloth dipped in warm water
  4. Blot up any remaining dishwashing liquid with a clean cloth
  5. Blot the area again with dry towels until you absorb all the moisture

Tip! I have two recommendations with this technique — add only a tiny amount of soap, and use a wet/dry vac to dry the area if possible. Removing all the soap is crucial, as residue can attract soil and worsen the stain. Too much dish liquid means you’ll have to rinse it aggressively and risk oversaturating your carpet. I recommend a wet/dry vac because, no matter how much you have to rinse, it will do the best job of extracting moisture without spreading it.

Why You Should Worry About Urine Stains

Removing urine stains as quickly as possible from your carpet is critical in preventing difficult staining and an ongoing odor problem. As the pee sits, it soaks deeper into the carpet and the padding underneath until it hits the subfloor. Damage to the carpet increases, and the urine becomes more and more challenging to reach.

Does Urine Permanently Stain Carpets?

In some instances, urine can permanently change the color of carpet fibers. The severity will differ based on the urine contents and the carpet design, with synthetic materials and stain-resistant coatings making for easier removal.

Regardless of the material, the urine smell will always be an issue. The bacterial breakdown of urea and other compounds releases mercaptans that give pet urine its familiar aroma. The embedded urine crystals continually draw in moisture and stay active to make the odor reappear for years, getting particularly nasty when the humidity is high.

The longer the urine sits, the more difficult it is for any stain and odor remover to effectively extract every bit of it from the carpet fibers and padding. And if you can’t eradicate the smell, it will only invite your pet to have repeat accidents in the same spot.

Health Impact of Urine Stains

Reducing the smell is critical for more reasons than comfort. While it typically takes a decent amount of urine to affect your health, microbes and the ammonia odor they produce can irritate the face and respiratory system. Children and individuals with weakened immune systems are at a higher risk of developing issues. If the moisture in the rug also creates mold, you have yet another air quality pollutant that can affect everybody in the house.

How To Prevent Urine Stains

Preventing pet stains from happening in the first place is always easier and faster than deep cleaning recurring accidents from the carpet. For most pet owners, proper training is the solution. If the problem has always existed, you must establish a new normal with the litter box or crate training.

New peeing issues may require a conversation with your vet. Underlying health issues like urinary tract infections can cause sudden inappropriate habits. Stress from changes in their daily routine or environment may further disrupt a pet’s behaviors and lead to urination issues. 

Age also plays a role. Intact kittens might spray throughout the house, while older pets could face mobility issues affecting their ability to access the proper peeing spot. Your vet will help you assess changes to pinpoint the issue’s cause and solution.

While you’re trying to solve the peeing issue, you can protect your carpet with a repellent spray. Though not a guaranteed remedy, products like Soft Clad Extra Strength Fabric Protector leave a resistant coating to keep moisture from soaking into rugs and upholstered items. Use it after cleaning, and future stains will sit on the surface to make cleanup as easy as possible.

Prevent Repeat Accidents

If your dog or cat is constantly peeing in the same spot, they’re likely smelling the area they marked. A thorough deep clean with a healthy amount of enzyme solution is essential to remove every trace of odor. But that can be a tall order, especially on an old stain. Although we might kill a smell to our satisfaction, pets only need the faintest odor to recognize their spot.

While you figure out a cleaning solution, you may need to block off the pee spot. Set up a physical barrier to keep them away, like a baby gate, or cover the area with a mat or piece of furniture. Alternatively, you can work with your pet to change the spot’s meaning. Rather than let them pee there, use that part of the room for play or feeding. They can soon make a new association, forgetting their old habit of using the spot to urinate.


Noah Hoit