MALIGNANT SKELETAL NEOPLASMS OF DOGS

A classification scheme is presented to discuss the biological behavio r of canine malignant skeletal neoplasms and their response to treatme nt. Osteosarcoma of the appendicular skeleton is the prototypical cani ne skeletal neoplasm, accounting for about 80 % of primary bone tumors . Local tumor control is readily achieved in dogs with appendicular os teosarcoma; inadequate treatment of metastatic disease is responsible for mortality. Osteosarcoma of the axial skeleton is discussed as a se parate clinical entity because there is very limited information on th e biological behavior of these neoplasms after successful local tumor control. Collectively, the non-osteogenic primary bone sarcomas repres ent a third important group of canine skeletal neoplasms. Bone metasta ses and fracture-associated sarcoma are grouped together because they account for the majority of skeletal neoplasms that affect the diaphys is of long bones (in contrast to the metaphyseal location of most prim ary bone sarcomas). Finally, skeletal neoplasms of small dogs (body we ight less than 15 kg) are discussed as a separate entity because of di stinct differences in histopathological type and site distribution com pared to the bone tumors of large and giant breed dogs.