Discovering a set-in dog urine stain on the carpet is frustrating, but it doesn't have to be disastrous. It's important to remove the stain completely because dogs have a tendency to return to the scene of the crime if they can still detect the scent of urine. Regular carpet cleaner may remove the discolouration, but a special cleaner containing enzymes is necessary to eliminate the odour, because the canine sense of smell is much more advanced than that of humans.
Clean the soiled area with a wet vacuum to remove all traces of old scented cleaners and deodorisers. Use warm water and do not add any type of cleaner.
Apply enzyme-based odour neutraliser to the affected area. Use enough product to soak the carpet and the padding underneath. Read the label closely and allow the cleaner to remain on the carpet for the recommended amount of time.
Clean with the wet vacuum again, this time using a carpet shampoo designed to remove pet stains and odours. Repeat if any sign of the stain or odour remains.
Allow the carpet to dry thoroughly.
Vacuum the area well.
Test the enzyme-based odour neutraliser on an inconspicuous area of the carpet to make sure that it does not cause discolouration.
Do not use a steam cleaner or hot water because the heat may make the odour and stain impossible to remove.