A ten-year-old female spayed Rottweiler presented to Cornell University hospital for animals for evaluation and possible surgical removal of a previously diagnosed multilobular osteochondrosarcoma. Diagnostics included physical exam, complete blood count, serum chemistry, urinalysis, thoracic radiography, abdominal ultrasound, lymph node aspirate, and a computed tomography scan. The mass was surgically excised, but histopathology revealed tumor cells were still present at the margins. She recovered uneventfully postoperatively and had no obvious recurrence at the primary tumor site after one year (the time this paper was written). In March 2008 she presented to the Cornell University Hospital for Animals Emergency Service. She was non-weight bearing on her right hide limb. Orthogonal radiographs of the hind limb revealed an aggressive bone lesion and a pathologic fracture on the distal femur, and thoracic radiographs revealed a multi-focal nodular lung pattern, consistent with pulmonary metastasis. The right hind limb was amputated, and no other therapy was pursued.