Here's a link to a site that carries at-home test kits. I didn't look to see if this is the one that tests the urine in the box by changing color. Otherwise, the vet has to get a sample from the bladder, not fun. Good luck!
Try this: http://www.animed.org/cats_home_health_kits
Many, many thanks for the link, but we could not bring it up. We're taking the cat back to the vet to see if they can get a urine test. Thank you again!