Royal Canin Feline Urinary S/O Morsels in Gravy Adult Wet Food is a complete dietetic feed for cats. Its urine acidifying properties and its low level of magnesium make it suitable for dissolving struvite stones and reducing their recurrence. Key Benefits: Struvite dissolution - Urinary S/O Feline effectively dissolves struvite stones. Urine dilution - Diluting urine decreases the urinary concentration of struvites and calcium oxalates. The larger urinary volume also ensures regular bladder wash out. Low RSS - Undersaturated urine is an environment where crystals cannot proliferate and so is unfavourable to the formation of struvite and calcium oxalate crystals.