Bone tumors can be benign or malignant and primary or secondary in dogs. Osteosarcoma (OS) is considered the most common primary bone neoplasm in dogs, which has high metastasis ability.

A retrospective histopathological study was performed over cases submitted to veterinary hospitals and clinics in Shiraz, the capital city of Fars province, south of Iran. Surgery and necropsy files of dogs submitted to clinics between 2010 and 2021 were retrospectively studied and cases suspected to bone tumors by were separated.

A total of 872 necropsy and surgical resection specimens from dogs referred to these clinics because of musculoskeletal defects were reviewed during this period, of which, nine dogs (six male and three female dogs) corresponded to bone tumors.

All of the tumors were diagnosed as osteosarcoma. The epidemiological and pathological findings of these tumors are reported.