The animal-dependent risk factors in canine osteosarcomas.

Canine osteosarcoma (OSA) is a malignant neoplastic tumor, which develops from the primitive mesenchymal stem cell, that has or can acquire the capacity to produce neoplastic osteoid with possible neoplastic bone formation. Predisposition of some dog breeds to OSA indicates genetic background of oncogenesis. The aim of the study was to characterize animal-dependent risk factors for canine osteosarcoma development in Poland. The study was conducted on canine patients diagnosed cytologically or histopathologically as having OSA, and data on age, breed, sex, as well as tumor location and character were recorded. No sex predisposition to OSA was observed, mongrels were significantly underrepresented. Large and giant dogs accounted for 47% and 35% of all pedigree dogs, respectively, and both proved predisposed to OSA. A vast majority of OSA developed in the skeleton (appendicular skeleton was more commonly affected than axial skeleton), soft tissues were affected less often. Rottweiler dogs are strongly predisposed to OSA, suggesting that the genetic background is involved in the tumor development, and indicates that dogs of this breed are a promising object for further studies on OSA pathogenesis.