What do you do if your cat's poop is yellow and you don't have a veterinarian?

There could be many different causes of the abnormal feces, depending on the cat's age, any existing conditions, history, etc. The only way to accurately diagnose the cause, and the appropriate treatment, if any, is to find a Vet for your cat. If there's not one in your town, perhaps there's one in a neighboring town, or maybe there's a mobile Vet servicing your area.