Spinal ataxia in a 2-year-old colt caused by a compressive primary vertebral osteosarcoma

Abstract

Neoplasia is a rare cause of ataxia in horses. This report describes a 2-year-old colt presented with sudden-onset ataxia in which a cervical vertebral osteosarcoma causing severe compression of the spinal cord was diagnosed. Radiological changes included a large osteolytic lesion in the vertebral body, the vertebral arch, the right cranial articular process and the right transverse process of C4, interrupting the borders of the vertebral foramen and the right transverse foramen. Myelography revealed a marked spinal cord compression. Necropsy confirmed the presence of a well-demarcated, invasive and firm mass protruding from the fourth cervical vertebral body that led to severe compression of the spinal cord. In spite of its strongly pleomorphic nature, the detection of osteoid confirmed the diagnosis of a central osteosarcoma of the combined type. To the best of our knowledge, a primary single vertebral osteosarcoma causing ataxia in a juvenile horse has not previously been reported, and findings of this case report could help in the diagnostic work-up of similar cases.