[Osteosarcoma in cats: epidemiological, clinical and radiological findings in 78 animals (1990-1995)].

In this study 78 cats with osteosarcoma were identified from biopsy logs and evaluated retrospectively regarding breed, sex, and age distribution, tumor location, clinical symptoms, radiographic findings, biologic behavior of the neoplasm, and outcome following therapy. There was no significant breed or sex prediffection among the cats. The average age was 10.1 years, with a range of less than one to over 17 years. 36 (46%) of the osteosarcomas were localized in the bones of the limbs, 42 (54%) were found in flat or irregular bones. The hind limbs (25 cases) were affected significantly more often than the front limbs (10 cases). The most prevalent sites were the distal femur, proximal tibia, the humerus and the digits. Four of the tumors occurred after osteosynthesis of a previous fracture. In most of the cats limb tumors were associated with chronic lameness. The skull was the most common site for tumors of the flat and irregular bones (35 cases), which involved the oral cavity in 27 cases. The most common symptoms were dental problems, deformations of the skull, and nasal discharge. The remaining tumors of the flat and irregular bones were located in the pelvis (3), vertebrae (2), scapula (1), and rib (1). Radiographic findings were very variable and ranged from lytic to purely osteoproliferative forms. With tumors of the flat and irregular bones, tumor recurrence was a common cause for euthanasia. Animals with tumors of the limbs had a good prognosis following amputation.