This case illustrates the importance of doing urine analysis for urinary stone cases. Sometimes, some vets may not do it to reduce veterinary costs for the owner. This is not good practice unless the owner rejected this test.
FIRST REPORT - SEP 2011 - Calcium oxalate urinary stones
http://www.sinpets.com/F6/20110920retrograde-hydrouropropulsion-singapore_ToaPayohVets.htm. The owner decided to feed just home-cooked food after the surgery.
SECOND REPORT - FEB 2012 - Struvite urinary stones despite giving "home-cooked food".