Struvite stones occur in conjunction with bacterial infection of the bladder. The action of the bacteria causes urine to become alkaline, which allows the formation of the stones. Calcium oxalate stones are also found in dogs. Formation of these stones is thought to occur with abnormally high urine concentrations of calcium and oxalic acid. I see these stones most frequently in the schnauzers.
Urate stones are the third type commonly found in dogs.
These stones form secondary to high levels of uric acid in the blood and urine. Dalmatians have a unique metabolic pathway that results in high uric acid levels, and as such are predisposed to urate stone formation. Urate stones are also seen in English Bulldogs, schnauzers, and Yorkies. They are generally small, smooth, and yellowish-green in color. I prefer to surgically remove bladder stones for several reasons.