How to Remove an Old Cat Urine Odor

You may love you cat, but the rancid stench of a set urine stain can make anyone second guess her undying devotion. Urinating outside the litter box results from a variety of reasons, including the desire to mark territory and stress from change or conflicts with other animals in your home. Additionally, un-neutered male cats communicate their mating status by marking with urine and are likely to re-mark that same spot if the odor remains. The unfortunately pungent odor of cat urine serves as a clear communicator of their identity and rank among other household animals.

Things You'll Need

  • Black light
  • Stiff-bristled brush
  • 1 gallon enzymatic cleaner
  • Paper towels
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Instructions

    • 1

      Pinpoint the exact source of the old cat urine odor by scanning the floor or furniture surfaces with a black light. Urine appears as a fluorescent patch under black lights. Turn off all the lights and hold the black light approximately 4 inches above the surface. Mark the urine-soiled area with a piece of paper or keep the enzymatic cleaner within arm's reach to avoid losing the spot. Enzymatic cleaner is available at any major pet supply store.

    • 2

      Squirt a circle approximately 3 inches outside the periphery of the urine spot for maximum coverage. Reach the urine-soaked padding beneath the carpet by saturating the entire area inside the circle. For throw rugs, turn over the rug and rug pad and repeat the saturation process on the underside. The amount of cleaner you should use depends on the size of the stain. Urine spots covering 1 square foot or more can easily require an entire gallon of enzymatic cleaner for total saturation.

    • 3

      Let the cleaner set for approximately one hour. Scrub the carpet vigorously using your stiff-bristle brush to help the cleaner neutralize all the urine-stained fibers. Soak cleaning foam that surfaces from the brushing with a paper towel and continue scrubbing for approximately three to five minutes.

    • 4

      Leave the scrubbed and saturated spot to air-dry. Complete drying can take up to two weeks depending on the circulation in the room and the type of carpet. Do not allow your cats into the room until the spot is completely dry.

    • 5

      Repeat the process with deeper saturation if the odor still exists after the first round of cleaning and drying. Expect to repeat the process multiple times if you unknowingly set the urine stain before using the enzymatic cleaner with chemical cleaners, hot water or a steam cleaner.