Are you able to catch a sufficient amount of urine yourself in a sterile container, refrigerate it, and get it to the vet asap?
I used to do this for Muffin so that she wouldn't have to stay at the vet's office. They would then test it and give me a prescription if one was needed.
Of course, my vet would do this because she knew me. I don't know if others would accept it or not.
Hope this helps some.
