Osteosarcoma of the tibiotarsus with possible pulmonary metastasis in a ring-necked dove (Streptopelia risoria).

An unknown-age, adult female ring-necked dove (Streptopelia risoria) was presented with an ulcerated mass on the medial side of the right tibiotarsus. Radiographs revealed severe boney lysis with proliferative periosteal reaction. Surgical amputation was performed at the level of the mid femur and histopathologic examination of the mass identified an osteosarcoma. At the 6-month recheck, the bird was in good condition with no evidence of tumor regrowth or metastasis; however, at 8 months, the dove was found dead. On necropsy, a large mass was present in the coelomic cavity invading the left pulmonary parenchyma. Histopathologic examination indicated a spindle cell sarcoma. Immunohistochemical staining for osteocalcin and osteonectin was performed on the confirmed osteosarcoma in the tibiotarsus and the spindle cell sarcoma mass. Results indicated positive intracytoplasmic immunoreactivity for osteocalcin and osteonectin in the confirmed osteosarcoma neoplasm. Very rare positive cytoplasmic immunoreactivity occurred in the spindle cell sarcoma.