This report describes the identification of C7-T1 discospondylitis on myelography and confirmed on postmortem computed tomography and necropsy in a 4-year-old Standardbred gelding as the consequence of jugular vein catheterization and secondary septic thrombophlebitis. Staphylococcus aureus was isolated from both sites. Diagnosis was complicated by non-specific signs of pain and the acute presentation of the gelding. Clinical signs included cervical pain, low head carriage, fever, and ataxia. Antimicrobial therapy and multimodal pain management were initiated but were unsuccessful. Spread of infection from septic thrombophlebitis has uncommonly been reported in horses, and this is the first reported case of secondary discospondylitis in this species.