Osteosarcoma is a malignant tumor that arises from cells that create bone. These tumors typically occur in middle-aged, large-breed dogs but can occur in any dog. Affected animals present with acute onset of lameness and swollen, painful bone(s). Radiographs show both breakdown of current bone and creation of new bone. Unfortunately, because of the highly malignant nature and the rich blood supply to bones, by the time osteosarcomas are discovered they have invariably already metastasized usually to the lungs but occasionally to other bones. Because of the disruption to normal bone secondary to the tumor, fractures commonly occur in conjunction with osteosarcoma.
Treatment unfortunately is not very successful. Radical surgical excision (such amputating affected limbs) with chemotherapy radiation therapy will typically give a year of survival time. Radical excision without chemotherapy results in average survival time of 4 months. No treatment gives a median survival time of 2-3 months. For osteosarcomas in sites not amenable to radical excision, radiation therapy may prove beneficial to reduce clinical signs for a time.
Osteosarcoma in cats is very similar except it is less aggressive giving mean survival times of around 4 years with amputation alone.
Enough of the etiology of this tumor is not understood to allow preventative measure to be elucidated.
For more information, please contact your veterinarian or email me..