Occurrence of Unilateral Posterior Polyneuritis in an 8-year-old Crossbred Mare

An 8-year-old Thoroughbred Turkoman crossbred mare was examined for right pelvic limb paresis and ataxia. The signs had been progressing through time. Neurological examinations revealed a gait deficit, right pelvic limb gluteal muscles atrophy, skin hypalgesia around the tail, perineum, and right pelvis. Hyperesthesia was found in the margins of anesthetic areas. Hypotonic anal sphincter and flaccid tail were also evident. Fecal and urinary retention were revealed by rectal palpation. At necropsy, the affected nerve roots in right lumbar, sacral vertebrae, as well as cauda equina were found to be significantly thickened and fibrotic with adhesions to the related vertebral bodies. Histopathological examinations confirmed the diagnosis of polyneuritis in this mare.