Things You'll Need
- Hand-held ultraviolet "black" light White chalk
Instructions
Operate in the cover of darkness. Pull all of the shades and curtains. Turn off all of the lights. Cat urine stains fluoresce red under ultraviolet light, be they old or new stains. You're better able to spot them when you use the light in a very dark room.
Sleuth for stains. Cover every square inch of flooring, but don't forget to shine your black light on vertical surfaces, including low-lying cupboards, doors and floor-to-ceiling windows. Some cats–especially those that are not neutered or spayed–are prone to territorial "marking" behaviors, in which they expel a jet of urine while standing, rather than squatting.
Mark the spot. A helpful suggestion from Best Friends Animal Shelter is using plain white chalk to draw an outline around the perimeter of each cat urine stain you find. This can be of big help when it comes time for clean-up--or if you simply want to demonstrate to your leasing agent or realtor the magnitude of the problem.
Survey the damage. Depending on the age of the cat urine stains and the saturation level, you may be able to remove fresh or new urine stains using an enzyme-based pet stain remover. Carpeting with nominal staining may be addressed with a thorough professional steam cleaning--as the Winn Feline Foundation notes, a home steam cleaner won't do the job. Areas of carpeting with old stains that have been repeatedly saturated may need to be cut out, or the entire carpeting removed.