Using a Blacklight (UV Light) to Detect Cat Urine Stains

One of the most frustrating experiences for a cat owner can be when your beloved pet urinates in the house. You will want to get rid of the smell at its source as soon as possible. But what happens if you look everywhere and can't locate the urine spot? Luckily, a black light, or UV light, is an inexpensive way to detect any cat urine stain, whether new or old, to find out where the cleaning needs to be done.

Where to find your black light

Hardware stores are a great place to find powerful UV or "fluorescent black" lights in decent sizes for a reasonable price. The bigger and more powerful the bulb, the smaller and more faded urine stains you will be able to find. Black lights made specifically for this purpose also can be found at pet stores, but they are generally more expensive and smaller than the hardware-store varieties.

Search in the dark

You will want to begin your search at nightfall or in complete darkness. This allows the stains to stand out much brighter under the black light and makes them easier to locate.

Sweep the area

Use a sweeping motion over the areas where you suspect there may be urine. Begin where the smell seems to be the strongest, and check all of your feline friend's favorite places -whether under the bed, behind the couch or next to your desk.

Mark your findings

You may find it is helpful to bring some chalk, tape or some other means of marking the urine stains as you find them. White chalk works especially well. It will be visible under the black light, and you can outline the entire soiled area so you can go back and clean it later.

Even if you think there is only one urine stain, it doesn't hurt to check for others, as well. Your UV light or black light should allow you to find even old, dried stains. They will show up as yellow or green under the light.