Management of arytenoid chondropathy and failed laryngoplasty in horses: 75 cases (1979-1985).

By use of endoscopy, 75 horses with respiratory noise and/or exercise intolerance were determined to have structural arytenoid cartilage abnormalities (60 primary, 11 after previous laryngeal surgery), or failed left laryngoplasty (4 horses) for laryngeal hemiplegia in which the arytenoid cartilage still appeared normal. Eighty-eight percent of the horses were either Thoroughbred (54 horses; 72%) or Standardbred (12 horses; 16%) racehorses; only 9 horses (12%) had occupations not related to racing. Seventy-six percent of the racehorses were 2 to 4 years old; all non-racehorses were greater than 4 years old. The male:female ratio was approximately 2:1. Of the horses with cartilage abnormalities, 28 had left-sided involvement, 22 had right-sided involvement, and 21 had bilateral involvement. Sixty-two arytenoidectomies were performed, 58 for cartilage abnormalities (22 left, 19 right, 17 bilateral), and 4 for failed left laryngoplasties. Overall, 45% of the Thoroughbred racehorses that returned to racing after arytenoidectomy raced successfully (50% left, 75% right, 22% bilateral); only 20% of the Standardbreds were able to race. Seventy-five percent of non-racehorses were able to return to their previous use. Many horses were retired intentionally after surgery.