Hill's Prescription Diet c/d Multicare Urinary Care with Chicken helps to maintain a healthy urinary tract and reduces the risk of urinary stone recurrence. Many cats suffer from FLUTD (Feline Lower Urinary Tract Disease), a complex and painful disease of the lower urinary tract, often associated with the formation of crystals that can lead to bladder stones. The two most common types of crystals that form in the urinary tract are struvite and calcium phosphate. Struvite crystals and stones tend to develop due to excess magnesium, ammonium and phosphorus in the urine and an alkaline urinary pH.