Royal Canin Veterinary Diets Urinary SO 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. Suitable for cats with urinary health concerns, ROYAL CANIN Urinary S/O helps to dissolve all types of struvite stones in your cats bladder. It also helps to dilute your cats urine to lessen the likelihood of crystal formation. Because one of the natural components of struvite crystals is magnesium, ROYAL CANIN Urinary S/O is exclusively formulated with a reduced level of magnesium to further support your cats overall urinary health. As part of the ROYAL CANIN Veterinary Range, it is important that this product is only given to your pet when recommended by a veterinary professional.Key Benefits Helps dissolve all types of struvite stones Urine dilution makes the urine less liable to form struvite and calcium oxalate stones Helps lower the concentration of ions