Hill's Prescription Diet c/d Multicare is a specialized urinary care dry food formulated for cats prone to struvite and calcium oxalate uroliths. This veterinarian-recommended diet contains 14% chicken and is designed to dissolve sterile struvite uroliths in as little as 14 days while preventing new crystal formation. This prescription diet features controlled levels of magnesium, phosphorus and calcium to decrease urinary concentration of struvite and calcium oxalate constituents. It maintains optimal urinary pH (6.2-6.4) to discourage crystal formation and contains potassium citrate (2 g/kg) as a urine alkalizing substance. The formula includes vitamin E and beta-carotene to help neutralize free radicals and combat urolithiasis. This therapeutic food requires veterinary authorization before purchase.