The Best Way to Get Old Pet Stains Out of Carpet
Pets make great companions, but they can also make great messes. If possible, clean pet urine stains immediately. Once they have dried and set into your carpet, it will take a little more effort to do the cleanup.
Finding the Stains
Sometimes you can smell the urine but are unable to locate it. Turn off the lights in the room and then use a black light to reveal set-in pet stains on the carpet.
A wet vac used with plain water might work to clean the stain; rent one at a home improvement store. Don't use a steam cleaner, because the heat may set the stain. A solution of white vinegar and water worked into the carpet with a brush should help remove both the stain and the smell. Blot the area dry with paper towels, and then use a commercial pet odor neutralizer according to the directions. Alternatively, sprinkle a generous amount of baking soda on the stain to neutralize the smell. Add a solution of 1 tsp. dishwashing liquid to 1/2 cup of hydrogen peroxide and work it into the carpet, and then vacuum the area after it dries. Avoid using ammonia to clean the carpet, since it smells like urine to a dog or cat.
If the urine has soaked down into the carpet padding, you may need to replace that section of carpet. Pets have a highly keen sense of smell and tend to return to the same area to eliminate. Cleaning the carpet won't do much good if the pet can still smell the urine below.