Originally posted by Randi
... at our vet, we got a packet of something called KatKor, it's from Specific. It comes in a little plastic bag and contains small grains and a pipette to suck the urine up. See if you can get it, it should be perfect for this purpose.
NOW she tells us!!!

Here's a link to KatKor, but it's not mentioned if it's available in the US .
KatKor product web site

And found this link, for a complete collection KIT available in the UK...
Vet urine collection kit