Many cats suffer from FLUTD (Feline Lower Urinary Tract Disease), a complex and painful disease of the lower urinary tract, frequently associated with the formation of crystals which can lead to bladder stones. The two most frequent types of crystal which form in the urinary tract are struvite and calcium phosphate. Hills Prescription Diet Feline s/d Urinary Care Chicken helps to reduce both of these types of urinary stones. Struvite crystals and stones tend to develop because of too much magnesium, ammonium and phosphorus in the urine and an alkaline urine pH. Hills Prescription Diet Feline s/d Urinary Care Chicken aids the disintegration of struvite stones by making the urine pH more acidic which helps to dissolve struvite stones. Hill's Prescription Diet s/d Urinary Care - Chicken at a glance: Complete dietetic food for adult cats Specifically developed for cats suffering with struvite stones Optimal urine pH: contains urine-acidifying DL-methioine and a tailored magnesium content