It sounds daunting to "collect a sample from a cat" but the wonderful gal at my Vets off ice gave me a "wonderful" solution...thoroughly clean a "pan" to use for the "litter"...for litter, use unpopped corn kernels...place the pan in a room, confining the cat, check often and when they "go" you have a clean sample, not absorbed by litter. Carefully pour in to a sterile container (I used baby food jar). Saved my Smitty's life (at age 3 and he's now 12) as he had urinary blockage and is now on special food.