Endoscopic evaluation of arytenoid function and epiglottic structure in Thoroughbred yearlings and association with racing performance at two to four years of age: 2,954 cases (1998-2001).
OBJECTIVE-To determine the association between results of endoscopic evaluation of arytenoid function (AF) and epiglottic structure (ES) in Thoroughbred yearlings and racing performance at 2 to 4 years of age. DESIGN-Retrospective case series. ANIMALS-2,954 Thoroughbred yearlings. Procedures-Records of yearlings that had endoscopic evaluation of the larynx between 1998 and 2001 were obtained, and results were graded by use of standardized scales. A modified Havemeyer scale (grade I, II.1, II.2, III, or IV) was used to evaluate AF; ES was graded on a scale of 0 to IV. Records were annotated if the epiglottis was subjectively short or narrow. Racing performance data were obtained from an online database. RESULTS-Horses with grade II.2 AF had significantly less earnings at 4 years of age, compared with earnings of horses with AF grades < II.2. Grade III AF was associated with fewer starts and less earnings at 3 and 4 years of age. No horses met the criteria for grade IV AF. Horses with ES grades > II had less earnings at 2 and 4 years of age, compared with earnings of horses with ES grades < II. A short epiglottis was associated with less earnings at 2 and 3 years of age. CONCLUSIONS AND CLINICAL RELEVANCE-Analysis suggested that yearlings with grade III AF had a decrease in athletic potential. Yearlings with grade II.2 AF, an ES grade > II, or a short epiglottis typically had decreases in racing performance. These factors should be evaluated carefully when developing purchase recommendations.
Garrett
Katherine S
KS
Rood and Riddle Equine Hospital, PO Box 12070, Lexington, KY 40580, USA. kgarrett@roodandriddle.com
Pierce
Scott W
SW
Embertson
Rolf M
RM
Stromberg
Arnold J
AJ
D000375:Aging; D000818:Animals; D001193:Arytenoid Cartilage / Q000502:physiology*; D004825:Epiglottis / Q000502:physiology*; D005260:Female; D006736:Horses / Q000502:physiology*; D007828:Laryngoscopy / Q000662:veterinary*; D008297:Male; D010805:Physical Conditioning, Animal; D012189:Retrospective Studies; D012420:Running; D013177:Sports