Osteogenic and fibroblastic osteosarcoma associated with the alveolar bulla and zygomatic arch in a pet rabbit

A 2.5-year-old, 2.9 kg, neutered, male domestic rabbit presented for sudden onset of sneezing and wheezing of 2-day duration. Upon physical examination, there was mild dyspnoea characterised by mild to moderate increased inspiratory effort and audible wheeze, without evidence of ocular or nasal discharge. An aggressive expansile lytic mass lesion of the right caudal maxilla extending into the zygomatic arch was identified on skull radiographs. Computed tomography confirmed a large heterogeneously contrast enhancing soft tissue mass associated with the lytic lesion, likely originating from the right alveolar bulla, extending into the zygomatic arch. Histopathological diagnosis was osteosarcoma with areas of osteogenic and fibroblastic patterns. Diseases of the nasal cavity are common in rabbits; while infectious rhinitis remains the most common diagnosis, increasing number of cases of neoplasms involving the maxilla and nasal cavity should remind clinicians to include it in the differential diagnosis list.