A 5-year-old, male mixed breed dog was presented to Gyeongsang National University Animal Hospital for bilateral mandibular open fracture by bite. The dog had loss of the teeth and injury of the oral mucosa. Radio-graphic and blood examinations were conducted. Fracture lines were observed between first premolar and second premolar, but temporomandibular luxation was not observed on radiographs. In serum analysis, elevated levels of CPK and LDH were found. The dog was anesthetized and prepared for aseptic surgery. Acrylic external skeletal fixator with Kirschiner wire was applied. Pin loosening and malalignment of the right fracture line was observed at 7 weeks after surgery. We applied Kirschner-Ehmer fixator and half pins during the second surgical procedure. At 4 weeks after a second surgical procedure, the fixator and pins were removed from mandible. The fractures were healed with no complications.