Thank you for the prompt reply.
Her vet wants a urine sample tomorrow to see if there's anything else going on. She does have urate crystals in her urine so she's on a food that has low protein. She does get plenty of sun.
It's hard to keep her out of the sun actually. It has just recently been getting warmer so she is able to lay in the sun for a while. She does wear sweaters, etc. especially since it's still chilly outside. I used to give her yogurt but she started refusing it. I'm going to drop off the urine sample tomorrow and talk it over with her vet. Thank you for the advice.