I took Biscuit back for a follow up ultrasound today. His kidney stone has dissolved and his bladder was clear! Biscuit's special diet worked so well he gained almost two pounds in four weeks...not that he needed to! From now on he will be on a preventative diet (thankfully less expensive than the last month) to help keep his bladder stone free!
Thank you for your prayers and good vibes over the last month--they helped! MEOW!