How do I find old, dried pet urine spots?

If you have a black light, use it to identify soiled areas and lightly outline the areas with chalk.

How to Get Old, Dried Pet Urine Stains Out

Found a dried pee spot you never saw happen, or a smell that keeps coming back? This guide covers old dog and cat urine on carpet, rugs, upholstery, washable fabrics and hard floors, using what the AKC, Humane World for Animals, the Carpet and Rug Institute, the ASPCA and UGA Extension say.

Why old urine is harder to remove

Time works against you. The AKC says: "While it's harder to remove the smell from dried urine stains, there are several effective methods to try." Part of the reason is how far urine can travel. When asked why a house still smells after cleaning, the AKC answers:

"Urine may have soaked into padding, upholstery, or wood. Repeated treatments or professional cleaning may be necessary."

Humane World for Animals (formerly the Humane Society of the United States) gives the same warning for carpet:

"Your job will be more difficult if urine has soaked down into the padding underneath your carpet. In some cases, you may need to replace portions of carpet and padding."

Sources: AKC, How to Get Rid of Dog Pee Stains and Smells; Humane World for Animals, pet stains and odors.

Step 1: Find every old spot

You cannot treat what you cannot find. Humane World for Animals says: "In some cases, old messes will have dried invisibly and be hard to locate." Its steps for finding them are:

"Use your nose to sniff out soiled areas."
"Examine the suspect area closely to catch hard-to-find soiling."
"If you have a black light, use it to identify soiled areas and lightly outline the areas with chalk."

The AKC adds that "Urine stain detectors help identify spots where your dog has peed, even if they're not wet anymore." For a full walkthrough, see how to find pet urine with a black light.

Sources: Humane World for Animals, Find older messes; AKC, How to Find Hidden Urine Spots.

Step 2: Rehydrate and extract carpet and rugs

The AKC's method for dried urine on fabric and carpets is: "Start by rehydrating and extracting the stain."

"Rinse the area with water"
"Use a wet-dry vacuum to extract moisture"
"Repeat until the area is as clean as possible"

For stains that have already set, Humane World for Animals says:

"Consider renting a carpet cleaner from your local hardware or grocery store. To get the smell of urine out of a carpet, use a high-quality pet odor neutralizer once the area is clean. Use carpet stain remover if the area still looks stained after it's completely dry."

Whatever product you use, the Carpet and Rug Institute (CRI) says "you should still pretest any cleaner on a scrap of carpet or in an out-of-the-way area of your carpet." It also says: "Follow the product's directions carefully. More is not better."

The AKC goes on: "If the smell remains, use an enzymatic cleaner specifically designed for pet stains." For more on carpet odor, see how to get pet urine smell out of carpet. If the spot is on a loose rug, our guide to getting dog pee out of an area rug covers care labels and checking the floor underneath. For marks left on light carpet, see yellow pet urine stains on light carpet.

Sources: AKC; Humane World for Animals; Carpet and Rug Institute, Cleaning and Maintenance.

Step 3: Keep heat and strong chemicals away

Humane World for Animals says:

"Avoid using steam cleaners to clean urine odors from carpet or upholstery. The heat will permanently set the stain and the odor by bonding the protein into any man-made fibers."

It also warns about common household products:

"Avoid cleaning chemicals such as ammonia or vinegar. Strong chemical odors may encourage your pet to reinforce the urine scent mark in that area."

Source: Humane World for Animals, pet stains and odors.

Upholstery and washable fabrics

The AKC notes: "Upholstery or car interiors may require deeper cleaning or specialized products designed for those surfaces." For a sofa, see how to get dog pee smell out of a couch; for a car, see how to get pet urine out of a car seat. For a leather couch, see how to get pet urine out of a leather couch.

Before you treat any fabric, UGA Extension's stain removal guide gives these cautions:

"Always read the care label before trying any stain removal method. Do not use any products or procedures prohibited by the care label."

"Always pretest each cleaning agent on an inconspicuous area first to determine colorfastness."

For bedding, throws and other machine-washable items, Humane World for Animals says: "Add a one pound box of baking soda to your regular detergent and wash as usual, air drying if possible." Then: "If you can still see or smell the soiling, wash again with an enzymatic cleaner". See our guide to getting pet pee smell out of clothes, bedding and towels.

Sources: Humane World for Animals; AKC; UGA Extension, Remove Stains From Urine.

Hard floors and wood

Wood is porous, so old spots can go deep. The AKC says:

"Urine can penetrate hardwood, making odor removal more challenging. Use a cleaner designed for wood surfaces to draw out absorbed liquid. In some cases, repeated treatments may be necessary to fully eliminate the smell."

If the color of the wood has changed, Humane World for Animals explains why:

"If the wood on your furniture, walls, baseboard or floor is discolored, the varnish or paint has reacted to the acid in the urine. You may need to remove and replace the layer of varnish or paint. (If you do so, make sure the new product is safe for pets.)"

For step-by-step floor cleaning, see how to clean pet urine from hardwood floors.

Sources: AKC, Removing Urine Odors From Hardwood; Humane World for Animals, Paint and wood damage.

When to call a professional

Some old stains are beyond a home cleanup. The AKC says: "If odors linger despite repeated cleaning, or if there are multiple or deep stains, professional cleaning may be the best option. This is especially useful for carpets, upholstery, and car interiors." The CRI says: "If necessary, call in a certified carpet cleaning firm that knows how to remove pet stains and odors permanently."

See our guide to why pet urine smell can come back after cleaning.

Sources: AKC; Carpet and Rug Institute.

Stop your pet from marking the spot again

An old spot that still smells can pull a pet back. Asked whether a dog will keep peeing in the same spot, the AKC says: "Yes, if odor remains. Thorough cleaning is essential to remove scent markers and discourage repeat behavior."

After cleaning, Humane World for Animals suggests:

"Once the area is clean, make it unattractive and/or unavailable to your pet and make the appropriate bathroom area attractive."

"Make previously soiled areas inaccessible or unattractive. If this isn't possible, try to change the significance of those areas to your pet. Feed, treat and play with your pet in the areas where they mark."

For cats, the ASPCA warns: "Do not clean up accidents with an ammonia-based cleanser." And if accidents keep happening, Humane World for Animals says: "If your pet is having regular accidents, have them checked by a veterinarian to rule out medical causes." Read more in why dogs and cats keep peeing in the same spot.

Sources: AKC; Humane World for Animals, pet stains and odors; Humane World for Animals, Stop Your Dog from Peeing in the House; ASPCA, Urine Marking in Cats.

Using P-Cleaner

P-Cleaner is the Pet Stain & Odor Eliminator Foaming Liquid from Pet Cleanup Kit. The product listing says: "Our rinse-free, water-based formula tackles the toughest stains and odors from urine, feces, vomit, and other organic messes on carpets, rugs, upholstery, and hard surfaces." It also says: "Works on carpets, upholstery, tile, and more.", "No scrubbing necessary" and "Odor-Free & Residue-Free". Check the care label and test a hidden area first, as the CRI and UGA Extension advise above. Follow the directions on the product label.

Still hunting for spots? The full kit includes a black light.

Buy P-Cleaner on petcleanupkit.com

Quoted from the petcleanupkit.com product listing.