Post-sale laryngeal endoscopy as a predictor of future racing performance

This is a well-conducted study with logical results showing a progressively worsening of racing performance with a worsening evaluation on a post-sale laryngeal endoscopic evaluation. Horses with normal laryngeal function and low-intermediate function performed statistically the same. Not surprisingly the high intermediate and abnormal laryngeal function performed significantly worse than the normal function group. For more on endoscopic exams of the larynx and grading systems see https://horseadvice.com/horse-equine/diseases/respiratory-system/laryngeal-hemiplegia/.
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Evaluation of postsale endoscopy as a predictor of future racing performance in an Australian thoroughbred yearling population
Aust Vet J. 2022 Feb 21. doi: 10.1111/avj.13155. Online ahead of print.
Authors
B J Ahern 1 , K de Klerk 2 , L R Hogg 3 , S A Vallance 4 , F R Bertin 1 , S H Franklin 5
Affiliations

1 The University of Queensland, School of Veterinary Science, Equine Specialist Hospital, Gatton, Queensland, 4343.
2 Hawkesbury Equine Veterinary Centre, 226 Hawkesbury Valley Way, Clarendon, New South Wales, 2756, Australia.
3 Kangaroo Island Veterinary Clinic, 252 Playford Highway, Kingscote, Kangaroo Island, South Australia, 5223, Australia.
4 Advantage Equine, Ascot Vale, Victoria, 3032, Australia.
5 School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5371, Australia.

Abstract

Introduction: Upper airway endoscopy of thoroughbred (TB) yearlings is commonly used in an attempt to predict laryngeal function (LF) and its impact on future race performance. The aim of this study was to determine if different grading systems and laryngeal grades were correlated with future performance.

Materials and methods: Postsale endoscopic recordings were obtained from an Australian TB yearling sale during a four-year period from 2008 to 2011. Horses were included if they had a diagnostic postsale video endoscopic recording and raced within Australia. Recordings were graded using the Havemeyer system and subsequently recategorised according to the Lane scale and two condensed scales. Performance data were sourced from Racing Australia and comparisons were made between groups.

Results: A total of 1244 horses met the inclusion criteria. There were no significant differences in sex or sales price between groups. There were no significant differences in the number of starts or wins between groups for any grading system. For the condensed Havemeyer scale, horses with intermediate LF were separated into two groups. Significant differences in earnings were found between ‘normal’ and ‘abnormal’ (P = 0.02) and ‘intermediate-low’ and ‘abnormal’ grades (P = 0.03). There were no significant differences between horses with ‘intermediate-high’ and ‘abnormal’ grades (P = 0.40). No significant differences were found between the two intermediate grades (P = 0.60) or between horses with normal LF and either ‘intermediate-low’ or ‘intermediate-high’ grades (P = 0.99).

Discussion: Resting LF in Australian yearling TBs assessed using a condensed Havemeyer grading scale had some predictive value for future racing performance. This information should be considered when performing yearling endoscopic examinations.

Keywords: endoscopy; laryngeal; performance; racehorse; sales; upper airway.

© 2022 The Authors. Australian Veterinary Journal published by John Wiley & Sons Australia, Ltd on behalf of Australian Veterinary Association.