A 12-year-old, intact female Toy Poodle and a 10-year-old, intact male Yorkshire terrier were referred with bilateral mandibular fractures, severe periodontal disease and teeth loss. In the second case, mandibular fractures were repaired with periodontal disease treatment. After a fallow-up period of 1 year, fracture healing was successful in the second case, however in the first case, bone healing was not satisfactory because mandibular fractures were repaired without the treatment of diseased teeth within the fracture line. Nonunion and inflammation of fracture sites, oral malodor confirmed in the first case and normal union of fracture sites observed in the second case. It suggests that the treatment of diseased teeth within the fracture line is mandatory for successful fracture healing.