Abstract: A litter for the accumulation of animal urine, such as a domestic cat litter, having at least one visual indicator chemically bound to the litter base material, and a method for making such litter have been discovered. The litter having the chemical indicator chemically absorbed thereon, rather than merely physically absorbed, permits the litter to be used not only as an effective mechanism by animal owners to determine potential health concerns with their animals; but because the indicator is chemically bound, the same litter may also serve as a useful diagnostic tool in a subsequent visit to a veterinarian. The litter base material must have the ability to exchange ions. Compounds to facilitate agglomeration or clumping of the litter when contacting urine may also be added to the litter base material.