ROYAL CANIN Veterinary Diet feline URINARY SO 30 and ROYAL CANIN Veterinary Diet feline URINARY SO IN GEL are complete and balanced diets for adult cats 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.