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)

Abstract

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.

Comparison of dynamic and resting endoscopy of the upper portion of the respiratory tract in 57Thoroughbred yearlings

“…The incidence of laryngeal asymmetry recorded in this study was lower than that previously reported in TB yearlings . All horses in this study had been through the sales process, which may have resulted in selection bias for horses without asymmetry.…”

Intra‐ and interobserver reliability estimates for identification and grading of upper respiratory tract abnormalities recorded in horses at rest and during overground endoscopy

“…Grading schemes were taken from the literature [7,[12][13][14][15][16][17] with modification to some schemes in order to give a numerical output for analysis (Supplementary Item 3). Two observers were American and/or European board-certified large animal/equine veterinary surgeons, the third boardeligible for the American College of Veterinary Surgeons (large animal) and the fourth an American and European board-certified large animal/equine veterinary internal medicine clinician.…”

Race performance following epiglottic entrapment surgery in Thoroughbred yearlings

“…Thus, the upper airway of most TB yearlings is examined prior to a sale and if epiglottic entrapment is discovered, it is surgically corrected. The upper airways of 2954 TB yearlings examined endoscopically at public auctions in central Kentucky identified no yearling with epiglottic entrapment ; however, our clinical impression is that the prevalence of epiglottic entrapment in the approximately 5000 TB yearlings examined in central Kentucky prior to the fall sales is ≤0.1%.…”