Abstract
Case Description—3 racehorses were evaluated because of poor performance or abnormal noise originating from the upper portion of the respiratory tract.
Clinical Findings—During maximal exercise, initial dynamic videoendoscopy of the upper respiratory tract revealed complete arytenoid cartilage abduction in 2 horses and incomplete but adequate abduction of the left arytenoid cartilage in 1 horse. Subsequent exercising endoscopic evaluation revealed severe dynamic collapse of the left arytenoid cartilage and vocal fold in all 3 horses.
Treatment and Outcome—2 horses were treated with prosthetic left laryngoplasty and raced successfully. One horse was retired from racing.
Clinical Relevance—Idiopathic laryngeal hemiplegia can be a progressive disease. Successive dynamic videoendoscopic upper airway evaluations were used to confirm progression of left laryngeal hemiplegia in these 3 horses. Videoendoscopy of the upper respiratory tract during exercise should be considered as part of the clinical evaluation of horses with signs of upper respiratory tract dysfunction.