Pathologic fracture in dogs with suspected or confirmed osteosarcoma

To evaluate clinical presentation of pathologic fractures associated with suspected or confirmed osteosarcoma in dogs and to assess treatment and survival times.

Case series.

Dogs (n=25) appendicular pathologic fracture.

Medical records (January 1997-May 2008) of dogs with pathologic fracture associated with a suspected or confirmed osteosarcoma were reviewed. Dogs were included if they had radiographic evidence of a pathologic fracture and a presumptive or definitive diagnosis of osteosarcoma. Radiographic details, histopathology, and/or cytology findings were recorded. Overall median survival time (MST) and MST of treated dogs were calculated. Age, sex, breed, and other concurrent treatment were evaluated.

Rottweilers, Irish Wolfhounds, and Greyhounds were the most common breeds represented. Most dogs had minor trauma and 60% had lameness preceding the fracture. Most commonly, fractures were nondisplaced with minimal comminution. None of the dogs had radiographic evidence of pulmonary metastases at admission. Immediate (13 dogs; 52%) and delayed (4; 16%) euthanasia were performed. One dog was not treated and died 90 days after diagnosis. Three dogs (12%) were treated by amputation alone, 1 (4%) with amputation and chemotherapy, and 3 (12%) with internal fixation using an interlocking nail. Overall MST was 1 day (range, 0-623 days) and MST of treated dogs was 406.5 days. Histologic confirmation of osteosarcoma was available in all treated dogs and 6 euthanatized dogs.

Treatment of pathologic fracture associated with presumptive osteosarcoma should be considered as an option to amputation or euthanasia if owners desire other options.