C6-C7 compressive myelopathy in a Saddlebred gelding

Abstract

An 11-year-old, Saddlebred gelding was referred to Cornell University Equine Hospital after a one week history of ataxia including stumbling, difficulty rising and 'dog sitting'. He was cast to his stall 2 months prior to presentation, but only hindlimb stiffness had been noted. On presentation, the patient was bright, alert and responsive. He had 4/5 hindlimb ataxia and 2.5/5 front limb ataxia. His mentation, cranial nerve examination, and bloodwork were within normal limits. A myelogram revealed a severe cervical spinal cord compression at C6-C7, kyphosis and fracture at the caudal aspect of he vertebral body. The gelding was taken to surgery to fuse C6-C7 intervertebral space by implantation of a kerf cut cylinder. The surgery was performed smoothly but in recovery, the horse became tetraplegic and displayed focal seizures of the head that were refractory to therapy. He was euthanized approximately 12 hours post-surgery. Necropsy confirmed a chronic severe C6-C7 stenotic myelopathy. Moderate acute subdural hemorrhage was present at C1-C3 spinal cord. The cerebrum showed locally extensive subdural edema.