Two dogs with bladder rupture possibly due to trauma and falty instrumentation are reported. Abdominal distension, depression and oliguria are found in both dogs. One also developed vomiting and fever. The other was noticed with rapid breathing. In clinical pathology, we found hyperphosphotemia, hyperkalemia, hyponatremia or elevated valnes in SGPT, BUN, creatinine values, and hematuria. In the 2nd case, the ascitic fluid analysis showed high values in BUN and creatinine. In the first case, a large amount of ascites was observed through an ultrasonographic scanning. In the second case, the location of rupture was demonstrated on ultrasonic images. Besides, we used the X-ray negative contrast imaging technique to make the diagnosis of bladder rupture, and treated the dog with surgery. Both dogs recovered and did well.