Abstract
In a case of urinary obstruction caused by cystoliths in a 6-month-old male cat, ultrasound and radiographic examinations detected a calculus (1cm in diameter) in the bladder. After cystotomy to remove the calculus, the urethral canal was opened by a modified perineal urethrostomy utilizing preputial mucosa. Two days after surgery, the patient was in good enough general condition to be discharged. The calculus was composed of mainly magnesium ammonium phosphate (>98%) and a small amount of calcium phosphate.
