ROYAL CANIN Veterinary Diet canine URINARY SO 13 (dry) and ROYAL CANIN Veterinary Diet canine URINARY SO (canned) are complete and balanced diets for adult dogs that have been specifically designed to ensure the production of a urine undersaturated with struvite and with a level of calcium oxalate saturation at which spontaneous homogeneous crystallization will not occur. This is achieved through the production of a large volume of moderately acidic, dilute urine and controlled magnesium, calcium, and oxalate levels. They have been formulated to reduce urinary RSS values for struvite, calcium oxalate, and brushite. Reduced RSS values help decrease the risk of urolith formation. The diets have been designed to undersaturate the urine for struvite, thereby, helping to promote dissolution (in conjunction with antibiotic therapy when appropriate).