Kidney stones in dogs and cats are occasionally seen and may cause urinary tract infections and other urinary tract symptoms. The stones, also known as uroliths, found in pets are very similar to those found in humans. Most of these stones are composed of mineral salts from common elements, including phosphorus, calcium, magnesium, ammonia, and carbonates. Types of kidney stones include struvites, calcium oxylate, urate, cystine, calcium phosphate, and silicate stones. Kidney stones normally do not affect the rest of your pet's body, unless the stones break off, leading to potential urinary tract obstruction.
Oversaturation of the urine with urine crystals is the biggest factor in stone formation in dogs and cats. This oversaturation may be caused by increased excretion of crystals by the kidneys, increased water reabsorption by the kidneys, and changes in the urine PH leading to crystal formation. Other factors in kidney stone formation include genetics, diet, frequency of urination, dehydration, and urinary tract infections. A combination of these factors often leads to a nest of cells and debris around which stone formation may occur.
Depending on the type of stone found in the urinary tract, certain dog and cat breeds have an increased incidence of forming kidney stones. Breeds predisposed to struvite stones include the Miniature Schnauzer, Bichon Frise, and Cocker Spaniel. Breeds prone to calcium oxylate stone formation include the Miniature Schnauzer, Shih Tzu, and Bichon Frise. Burmese, Persian, and Himalayan cats may also be at risk.