Royal Canin Veterinary Diet Urinary Moderate Calorie Cat Food 12x85g is formulated for the nutritional management of overweight adult cats with lower urinary tract disease. The formula contains reduced calories for overweight cats to help limit weight gain & help maintain an ideal body weight. With low levels of magnesium and urine acidifying properties, the formula helps lower the concentration of ions which contribute to the crystal formation. Royal Canin Veterinary Diet Urinary Moderate Calorie Cat Food 12x85g safely dissolves struvite stones and helps to reduce the risk of reoccurrence of the stones & crystals by diluting the urine for your cat. This wet diet compliments the Royal Canin Veterinary Diet Urinary S/O Dry Cat Food. diets should only be used with the professional advice of your Veterinarian