That refers to the most common type of urolith found in ferrets,
struvite, which are usually seen in diets too high in vegetable
protein. Infection can also cause struvite stones.

There are additional types of urinary stones found in ferrets besides
these two.

BTW, pH of the urine needs to be lowered in those w struvite stones,
but raised in those with cystine stones. That is why ferrets with
struvite stones may also need an acidifier but that should never be
given to a ferret with cystine stones.

I highly recommend that people read up on the TYPES of uroliths --
which literally means urinary stones -- and that any such stones or
slush goes to urolith labs to learn the type, and that urine pH be
checked by the treating vet, because what needs to be done can be
polar opposite depending on the stone types.

[Posted in FML 7963]