Our two ten yr. old male Burmese cats both had surgery for bru(bleep)e bladder stones recently in spite of changing to all wet urinary foods,Purina St/Ox and Walthams SO pouch. The smaller cat at 7 lbs. had calcium oxalate stones removed a yr. ago and that was when the food switch was made. Looking for how to prevent both these stones. Your input very much appreciated.

