Royal Canin Urinary SO is a veterinary-exclusive dry cat food developed to nutritionally support your adult cat’s urinary tract and bladder health. This formula promotes a urinary environment unfavorable to the formation of both struvite and calcium oxalate crystals. It increases the amount of urine your cat produces to help dilute excess minerals that can cause crystals and stones. Relative Super Saturation (RSS) methodology is used to help lower ion concentration in urine, which contributes to stone formation. And this specialized nutrition, with a reduced level of magnesium, helps dissolve pure struvite stones and prevent struvite stones from forming. Lower urinary tract issues may be a recurring concern for some cats. Talk to your veterinarian about keeping your cat on this urinary cat food for long-term urinary support.