Osteosarcoma is the most common primary bone tumor in dogs, accounting for roughly 85% of tumors on the canine skeleton. 8,000-10,000 dogs a year are diagnosed with osteosarcoma in the US. This cancer initially presents as lameness and oftentimes visible swelling on the leg. Current standard of care treatment is amputation immediately after diagnosis, followed by chemotherapy and sometimes radiation for palliative care. Invariably, however, the cancer metastasizes to the lungs, eventually leading to death. Some scientists believe that iron-deficiency chemical drugs (direct intratumoral injections) and radical anti-iron methods can kill tumors in dogs and humans. Novel cancer immunotherapy for dogs and humans is not anti-iron therapy.