Prevalence of pharyngeal, laryngeal and tracheal disorders in thoroughbred racehorses, and effect on performance
Section of Equine Medicine, Department of Companion Animal Clinical Studies, South Africa; Section of Epidemiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa; School of Veterinary and Biomedical Sciences, James Cook University, Townsville, QLD 4811, Australia
Endoscopic examinations were performed on 1005 thoroughbred racehorses in South Africa a mean (sd) 24 (12.3) minutes after racing, to determine the prevalence of pharyngeal, laryngeal and tracheal disorders, and to determine the relationship of these disorders with performance (number of wins and placed finishes). Overall, there was a low prevalence of grade 2 and 3 laryngeal function (LF) (2.2 per cent), grade 4 LF (0.6 per cent), epiglottic entrapment (1.3 per cent), subepiglottic cyst (0.2 per cent) and epiglottic deformity (0.6 per cent), while a higher prevalence of grade 2 to 4 pharyngeal lymphoid hyperplasia (PLH) (63 per cent), laryngeal debris (435 per cent), tracheal debris (21 9 per cent), tracheal mucus (99.5 per cent) and tracheal cartilaginous nodules (TCNs) (6.8 per cent) was observed. Performance was not affected by the presence of epiglottic deformity, grade 2 and 3 IF, grade 4 IF, debris within the trachea or larynx, or epiglottic entrapment. Grade 3 PLH occurred in younger racehorses; performance was impaired in horses with grade 2 and 3 PLH. Furthermore, TCNs were more prevalent in male racehorses and were associated with better performance.
animal; animal disease; animal experiment; article; female; horse; horse disease; larynx disorder; male; pathophysiology; pharynx disease; running; sport; trachea disease; Animals; Female; Horse Diseases; Horses; Laryngeal Diseases; Male; Pharyngeal Diseases; Physical Conditioning, Animal; Running; Sports; Tracheal Diseases; Congiopodidae; Equidae