Helping to reduce the risk of bladder stones formation
Struvite is the main urinary stone that occurs in young cats. It's composed by phosphorus, magnesium and ammonia and usually occurs in alkaline urine. The molecules are formed as a result of electrostatic attraction forces of these high affinity different ions. Several molecules bind, resulting in a struvite crystal (microscopic) and several crystal then bend together to form a stone (macroscopic). That is why is important to reduce the amount of these minerals arriving to the urine by decreasing its intake.
Changing the urinary pH helps to prevent these stones, as a lower pH weakens the affinity between ions which results in a lesser tendency for these ions to bind forming a struvite crystal and stone.
As kidney function may decrease with age, it is even more important to watch out the levels of minerals intake by mature old cats. That is one of the reasons why Hill's has developed different formulas for young adult and mature adult cats.