CRICOPHARYNGEAL-LARYNGEAL DYSPLASIA IN A HORSE WITH SUDDEN CLINICAL ONSET IDIOPATHIC LARYNGEAL HEMIPARESIS

A 7-year-old Thoroughbred racehorse developed loud exercise-related re spiratory noises and exercise intolerance over a short period. Examina tion showed congenital cricopharyngeal-laryngeal dysplasia (rostral di splacement of the palatopharyngeal arch) and also left sided idiopathi c laryngeal hemiparesis, the latter appearing to be of recent clinical onset. The animal developed colic some months after laryngeal surgery and a nephrosplenic entrapment was surgically corrected. Aerophagia a nd regurgitation worsened after surgery and, after developing inhalati on pneumonia, the animal was destroyed. Post-mortem examination confir med the presence of idiopathic laryngeal hemiparesis and of cricophary ngeal-laryngeal dysplasia which had some previously undescribed laryng eal muscle abnormalities.