Magnetic resonance imaging in a lamb with compression of the thoracic spinal cord by an abscess.

INTRODUCTION: This report describes a two-month-old Ouessant ram lamb with hind limb ataxia, knuckling and falling attributable to an abscess in the thoracic vertebral region. A swelling palpated adjacent to the spinous processes of the 9th to 12th thoracic vertebrae was identified via ultrasonography as an abscess located on the transverse processes of these vertebrae. Magnetic resonance imaging of the lamb postmortem revealed that the abscess had invaded the vertebral canal through a channel at the level of the 9th thoracic vertebra causing extradural spinal cord compression. Postmortem examination confirmed these findings, and histological examination showed acute spinal cord degeneration.