Calcium oxalate uroliths are most commonly encountered in Miniature Schnauzers, Lhaso Apsos, Yorkshire Terriers, Bichons Frises, Shih Tzus, and Miniature Poodles. They are more common in males than females, and more common in older than young dogs. Dogs that form abnormal nephrocalcin are also predisposed to calcium oxalate uroliths. Dietary risk factors for calcium oxalate uroliths include excessive calcium supplementation or excessive calcium restriction, excessive oxalic acid, high protein, high sodium, restricted phosphorus, restricted potassium, and restricted moisture (dry formulations). Dogs with hyperadrenocorticism or hypercalcemia are predisposed to calcium oxalate urolith formation.