Botryomycosis‐like discospondylitis of the thoracic spine in a Friesian horse with severe bilateral pelvic limb ataxia and paresis

Abstract

SummaryBotryomycosis is an uncommon chronic bacterial pyogranulomatous infection of cutaneous and, rarely of visceral origin, that can rarely invade the osseous tissues. An 8‐year‐old Friesian gelding was presented with severe bilateral hindlimb ataxia and paresis of 2‐weeks' duration. Radiographic examination revealed a large osteolytic lesion at the T10‐T11 intervertebral disc space. Post‐mortem examination revealed discospondylitis with abscess formation and histological presence of pyogranulomatous inflammation with coccoform bacteria rimmed by Splendore‐Hoeppli material. Staphylococcus aureus was identified by bacteriological examination. This case report describes the clinical presentation, imaging features and post‐mortem findings of a Friesian gelding presenting with severe bilateral hindlimb ataxia and paresis caused by compression and degeneration of the spinal cord due to a botryomycosis‐like thoracic discospondylitis. Botryomycosis‐like infection should be considered in the differential diagnosis of focal expansile bone lesions demonstrating diffuse osteolysis, sclerosis and interrupted bone margins.