2015 ACVS Foundation. Tumors originating from the vertebral bodies or epidural space are relatively uncommon in veterinary medicine, while neoplasia developing from the intervertebral disc itself has not been reported. Tumors arising from vertebrae or within the epidural space may mimic intervertebral disc herniation (IVDH) on currently available imaging and are discussed in this chapter. Osteosarcoma is the most common tumor of bone in the dog. Chondrosarcoma is the next most common primary bone tumor and approximately 61% originate in flat bones as opposed to the appendicular skeleton. Approximately 50% of reported spinal tumors in dogs are located within the epidural space. Nerve sheath tumors are the most common type of spinal tumor according to one source and may be extradural, intradural/extramedullary, or intramedullary. The advent of high field magnetic resonance imaging (MRI) has significantly reduced the possibility of misclassifying tumors originating within vertebrae as IVDH.
