3. Studies of Cancer in Animals Seen in Veterinary Practice

3.1 Dogs 3.1.1 Case reports Case reports in the veterinary literature describing malignant tumours at the site of metallic implants and miscellaneous non-metallic foreign bodies in dogs are summarized in Table 37. Sarcomas developed after metallic implants or deposition of other foreign bodies. The time lapse from implantation to sarcoma development was reported in 48 individual cases and ranged from one to fifteen years, with an average of approximately six years. The orthopaedic devices included pins, nails, plates and wires or combinations of these materials. Sarcomas developing adjacent to implants were most commonly found in the diaphyses of long bones (approximately 85%) in large breed dogs; about half occurred in the femur. The male:female ratio was 1.8:1. Non-metallic and miscellaneous foreign bodies included a surgical sponge, a pacemaker, glass and a total hip prosthesis. The sarcomas most commonly reported to develop at sites of implantation of foreign objects were osteosarcoma, chondrosarcoma, fibrosarcoma and undifferentiated sarcoma.