There is such a thing known as feline kidney stones, which basically are kidney stones found in cats.

Kidney stones are basically crystal aggregations, or solid matter compositions of materials in urine. They are typically exited from the body, taking on the same "pathways" which urine takes in exiting the body. It is when they grow in size, or bunch up, when they become problems, standing as "clogging" materials, greatly affecting the urinary system in a negative way

Kidney stones come in various sizes and are composed of different materials, which basically stand as the vantage point which defines their type of kidney stone variety. There are kidney stones known to be a small as a grain of sand, while there are also kidney stones which grow to about the size of a tennis ball. Once kidney stones grow to sizes enough to clog up the urinary system, this is when they pose to be quite large problems.

The causes of feline kidney stones, understandably are not much different from the causes of kidney stones in humans, with diet being one primary factor.

As cat kidneys process urine, what a cat eats stands to be one great factor when talking about feline kidney stones.

Water and a cat's drinking habits also stand to be another factor in the cause of prevalence of feline kidney stones, as well as other more "out of one's hands" factors like genetic defects and general illnesses.