Does dog urine show up under black light? Simple and Effective Tips

Dog urine black lights can be great tools for uncovering spots where your dog is peeing in the house because of how they work. Although many UV black lights appear to emit a purple glow, the frequency at which they emit light waves reveals the presence of phosphors in substances. Phosphors are present in liquids, fabrics, and other materials, and give off a luminescent color after being energized by light. Once they collect this energy, the phosphors slowly process it and release it, emitting a faint glow in the process.

If the room you’re looking at lights up under your UV black light, however, you know you have a real issue with dog peeing or marking that you’ll need to address right away.

These two pictures were taken of the same drape. The picture on the left is how it appears during the day to the naked eye. After using a dog urine black light (r.), however, we found multiple dog urine stains.

3. See Whether You Need to Break Your Dogs Pee Pad Habits—While pee pads can be a helpful tool when housebreaking your pet, using them too frequently could confuse your dog into thinking its acceptable to pee indoors. If you notice your dog is peeing around areas where he or she used to go potty on for pee pads, you may need to consult with your trainer to address this issue and develop a plan of attack for truly housebreaking your dog.

2. Use Commercial Repellants to Deodorize Pee Spots—If the damage isn’t significant, use a commercial pet deodorizer and stain remover spray to neutralize any scents and clean any urine spots you may have discovered. If you have multiple dogs, failing to quickly deodorize urine-stained areas of your home can lead them to start marking their territory on top of these spots in retaliation. As one major study from the University of Wisconsin showed, its very common for multiple dogs in a household to resort to urine marking and leg-lifting to show off their social dominance–regardless of whether they were spayed or neutered. Deodorizing sprays can provide temporary relief, though it may not completely stop this natural behavior from happening in your home.

How to Use the UV Flashlight Pet Urine DetectorLots of things glow under UV light, including carpet fuzz, bugs, and toys. Vacuum the area first so that you don’t get distracted (or horrified) by all the shiny detritus revealed.

Focus on dry urine. The UV light only creates a glow with dry urine. If its still damp, or youre in a humid area so the carpet or other surface absorbs moisture, you wont see the glow. Thankfully, youre likely to notice an area thats wet before you need the light—save it for when you cant find the source of the smell.

Search in the dark. Youll have the greatest contrast in a dark room, so get the best results by using it in the evening with the lights out. When theres too much light, it dilutes the glow and makes stains hard to see.

Get up close. The UV Flashlight Pet Urine Detector works best at a distance no further than 24 inches. Standing up and waving the light around may miss soiled areas, so invest in knee pads to crawl around (or get your kids to do the legwork). Try to find the exact locations of suspect odors to target the area. This light wont work well on all urine stains as a cat urine detector, but getting up close will help improve the effectiveness.

Look for yellow. Lots of things glow under a black light (white, green, blue, even red) but look for the pale yellow color that a urine stain creates. Pet urine stains look different depending on whether the dog squatted or leg-lifted. Stains can look like a pooled puddle, drips, or splatters on the floor, furniture, or walls. Remember that bright white glow spots are more likely from carpet cleaners, spilled drinks, or even wallpaper glue.

Mark the dirty deed. Once you turn off the light, the spot disappears. So be sure to use tape, chalk, or even a sticky note to mark the stain so you can clean up the pet mess.

How to Use a Blacklight to Find Pet Urine

In our opinion and the opinion of many pet lovers, blacklights are an excellent way to find those tricky urine stains.

However, keep in mind that urine will not, as many believe, show up bright white under a blacklight. Instead, it will be a bright yellow. Some people find it easier to spot urine with a blacklight at night.

At nighttime, with the lights off in your home, you can find urine by sweeping any suspected area with your blacklight. It’s best to hold the blacklight about 1-3 inches away from the carpet or other surface you’re examining. Look for that bright yellow color!

Once you’ve found the urine stain, you can treat it with your favorite stain and odor removing product. Of course, we recommend Pet Odor and Stain Eliminator or one of our other safe products. To learn more about why our products work so well at removing urine stains and odors as well as how the actual process works, please check out our article, How to Remove Pet Odor.

Our products (and other bacteria-based products) use bacteria to digest stains and/or odors. Bacteria naturally produce proteins or are partially composed of proteins.

There is some talk around the interwebs about bacterial proteins being dangerous. The reality is, while some proteins, like botulinum toxin, are dangerous, the vast majority of proteins are not. ALL enzymes, for instance, are proteins. Like we said above, bacteria naturally produce proteins, and bacteria themselves are partially composed of proteins! Bacteria can also leave harmless remnants of proteins behind.

In effect, just because you’re dealing with a protein produced or contained within a bacterium doesn’t mean it’s toxic. At Unique, our bacteria are completely safe. As regular bacteria, they leave behind traces of safe proteins. We’ve discovered that these traces of proteins contain phosphorus atoms, making the proteins fluoresce under a blacklight.

What this means is that, after cleaning with our products, you will likely see a very faint and dull glow under a blacklight. This is just the harmless proteins left behind by the bacteria. They won’t be bright yellow like the urine. Instead, they will show up as a dull and pale yellow that will probably be very difficult to see.

How to find Dog & Cat Urine Odor with a Blacklight or UV light

Even a small urine stain on the carpet encourages your dog to continuously re-mark that spot. Unfortunately, urine stains arent always obvious, especially on dark carpets — and you cant remove what you cant find. Under the ultraviolet light of a black light, dried urine crystals are easy to see.

Vacuum the carpet thoroughly before using the black light. In addition to urine, your black light will illuminate lint, fur and other small particles. Although the differences in color and smell make it hard to confuse a urine stain with lint, removing these items ahead of time allows you to hone in on the urine-stained spots.

Turn off the lights, close the shades and shut the door. Ultraviolet light illuminates urine most effectively when the room is completely dark. Wait until night if the carpeted room has windows. The darker the room, the easier it will be for you to locate those sneaky urine stains.

Put on your safety goggles, available at any hardware store, to protect your eyes from the ultraviolet light. Especially if you anticipate spending more than a few minutes mapping the spots on the carpet, your eyes will need protection. Once you have on your protective eyewear, grab your black light and your masking tape and turn off the lights.

Scan the carpet by holding the black light 1 to 2 feet above the floor. Keep in mind that ultraviolet light will turn food and fluid stains various shades of fluorescent white, blue or green. Urine stains, however, are not bright. Urine crystals are dull in color, and will appear as pea-soup green or brownish-yellow.

Confirm that the spot you found is indeed urine with the old smell test. Urine, of any type or age, has an odor that is unmistakable. Once youve confirmed that the stain is urine, stick a small piece of masking tape on the center of the stain so you know where to concentrate your cleaning efforts. For larger stains, use several pieces of masking tape to mark the outer limits of the stains perimeter.

Christina Bednarz Schnell began writing full-time in 2010. Her areas of expertise include child development and behavior, medical conditions and pet health. She holds a Bachelor of Arts in international relations.