Traumatic brain abscess due to Streptococcus equi subspecies zooepidemicus in a Foal

Bacterial infection of the equine central nervous system is rare. This report describes the clinical features, computed tomography (CT) findings, and postmortem results of a 3-month-old female Quarter Horse with an intracranial abscess. Clinical signs included seizures, depression, and bilateral blindness. CT imaging demonstrated a large space-occupying lesion in the left cerebral hemisphere, associated with a frontal bone fracture. Necropsy and histopathology confirmed the presence of an abscess secondary to head trauma. Bacterial culture identified Streptococcus equi subsp. zooepidemicus as the causative agent. Brain abscess should be considered a differential diagnosis in foals presenting with seizures and other acute neurological abnormalities.