A five year old male Rottweiler presented with persistent nasal discharge and intermittent epistaxis of duration of over one year, was diagnosed with maxillofacial osteosarcoma based on radiographic findings of the skull and histological findings of the mass. Physical examination revealed severe facial swelling and distortion. Radiographs showed severe lysis of the incisive and maxillary bones, with a typical moth-eaten appearance. In addition, there was distortion of the outline of the nasal turbinate and severe soft tissue swelling. There was no evidence of metastasis both on thoracic radiograph and abdominal ultrasound. Haemato-biochemical parameters revealed moderate anaemia with neutrophilic leukocytosis, elevated serum alkaline phosphatase, hypernatremia, hyperkalemia, hypochloremia and metabolic alkalosis. Cytological evaluation of the neoplastic mass revealed numerous moderately pleomorphic round, oval, polygonal, spindle-shaped or elongated irregular cells with abundant osteoid at their background. Histologically, the neoplastic mass has different appearance with production of osteoid and invasion of the surrounding tissues. The tumor matrix contained variable quantities of osteoid, cartilage and collagen. The dog was euthanized due to poor prognosis of obtaining tumor free margin after surgical excision. It was recommended that radiographic examination of the skull should be part of the routine assessment of dogs presented with epistaxis.
Key words: Maxillofacial, Axial, Osteosarcoma, Dog, Rottweiler