Yearling laryngeal function grades II.2 and below are not associated with reduced performance.
Authors: Hardwick Josephine L, Ahern Benjamin J, Crawford Kylie L, Allen Kate J, Anderson Brian H, Rose Kim J, Franklin Samantha H
Journal: Equine veterinary journal
Summary
# Yearling Laryngeal Grading and Racing Outcomes: What the Data Actually Tell Us Post-sale endoscopic examinations of 5,175 Australian Thoroughbred yearlings (2018–2019) were retrospectively analysed to clarify whether laryngeal function grades at yearling sales predict career race earnings, with multivariable modelling controlling for confounding variables. The cohort was heavily skewed towards normal or near-normal function: 29.8% graded I, 49.0% graded II.1, 16.5% graded II.2, with more severe grades (III.1–III.3) representing only 4.6% of the population; concurrent endoscopic abnormalities including intermittent dorsal displacement of the soft palate (24.4%), arytenoid mucosal lesions (7.6%) and ventroaxial luxation of the corniculate process (1.5%) were also documented. Median career earnings showed only modest differences between grades I, II.1 and II.2 (£45,095–£45,315 versus £38,610 for II.2), with statistical analysis confirming no significant performance disadvantage for grade II.2 horses compared with the combined grade I/II.1 referent group; meaningful performance decline emerged only at grade III.2 overall and at grades III.1 and III.2 in horses aged four years or older. For purchasing and racing decisions, these findings suggest that yearling laryngeal function grades within the normal-to-mild range (I–II.2), which encompass 95% of the yearling population, should not be used as sole exclusion criteria or heavily weighted factors in selection, though monitoring for progression in grade III animals and assessment of concurrent airway pathology
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Practical Takeaways
- •Yearlings with mild-to-moderate laryngeal dysfunction (grades II.2 and below) should not be penalized at sales or excluded from racing, as they perform similarly to normal horses throughout early careers
- •Only the most severe laryngeal grades (III.1–III.2) warrant concern for reduced future earnings, particularly as horses mature beyond 4 years old
- •Consider age-related performance when counseling clients about laryngeal grades: early career performance may be normal, but problems emerge in older horses with severe dysfunction
Key Findings
- •95% of yearlings had YLF grades I, II.1, or II.2 with minimal performance differences between them
- •YLF grades II.2 and III.1 showed no significant difference in career earnings compared to grades I/II.1
- •Grade III.2 horses earned significantly less overall ($46,015 less; p=0.04) compared to grades I/II.1
- •Grade III.1 and III.2 horses had substantially reduced earnings at ≥4 years old compared to normal grades