I thought cat pee showed up under black light?

One of the furballs has been thinking outside the box (I know why and when it started, just haven’t, you know, been able to quite stop it.) I got a UV flashlight to spot the spots, so I can Nature’s Miracle them away and put a litter box on top of them, etc. I thought cat pee showed up like that? I found a shirt wet with known pee tonight, though, and it did not show up. (It’s been more difficult to tell than I expected, because I forgot that, you know, white stuff was going to show up too.) Am I just dumb, or deluded?

UV lights aside, maybe it’s time for Heathcliff to become an “outdoor kitty” . . . . .at a very, very busy intersection, if ya know what I mean . . . . . .

I’ve seen it work with a black light before. It was a device specifically marketed for that purpose, but as far as I could see it was just an ordinary black light. Worked very well.

Maybe the pee needs to dry first?

Cute. Just adorable.

In my experience, cat urine needs to be dry to fluoresce, and it does so with a distinct yellow color.

Hereis a link about it, it seems to do a nice job explaining how to spot urine.

Turn the room light off, before trying the light.:smiley:

Oh my god, it’s like a Jackson Pollock painting!

Landlord and pet owner here.

Cat pee definitely shows up under a black light. So does dog pee, people pee, various foods and drinks… anything with phosphorus in it will glow under a black light. Pee puddles will be no more than about 3 or 4 inches in diameter on the carpet, but spread out when it gets to the padding. If you see a suspicious spot, you have to confirm it with your nose.

Don’t even bother trying to address the problem on the carpet alone. You’ve got to get to the padding underneath, and sometimes the subfloor and tack bars (those strips of wood that hold the carpet down).

It isn’t carpet, it’s hardwood floors, rugs, and, god, laundry in laundry baskets and such.