A cross breed dog (6-year-old, 6 kg, intact male) was referred with hematuria. The dog had been treated for years owing to the urinary bladder calculi. On abdominal radiography, prostatic calculus was demonstrated in the prostatic area. In addition, ultrasonography and computed tomography (CT) scan would confirm that the part of calculus protruded within the prostatic urethra. The patient underwent a prostatolithotomy and traumatic prostatic urethra was carefully sutured and the omentum was filled with the prostate lumen. A crystallographic analysis of the stone showed 80% magnesium ammonium phosphate (struvite) and 20% carbonate apatite. The leakage of the urine was not observed post-operation and the hematuria improved and there was no specific problem at the 6 months follow-up.