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Journal of the South African Veterinary Association2020; 91; e1-e5; doi: 10.4102/jsava.v91i0.2013

Endoscopic recurrent laryngeal neuropathy grade prevalence in a sample of thoroughbred yearlings at public auction in South Africa (2013-2019).

Abstract: Endoscopy of thoroughbred (TB) yearlings at public auctions is common in South Africa. Laryngeal function (LF) is a common concern of buyers of young TBs. Cancellation of sale because of LF abnormalities is a concern for both the vendor and the buyer, with recurrent laryngeal neuropathy (RLN) being a common cause of sale cancellation. The aim of this descriptive study was to determine the prevalence of RLN at South African premier TB yearling sales. This study was designed as a retrospective descriptive analysis of upper respiratory tract (URT) endoscopic examinations to determine RLN grade, performed at two premier TB yearling sales in South Africa. Results of buyer-requested endoscopic examination from 2013 to 2019 were included. Results from the yearling sales were analysed for prevalence of RLN grade (using Rakestraw's 4-point system) and compared to similar previously published studies. For analysis of effects of gender on RLN grading, horses were grouped and Fisher's exact test was used to determine if there was a relationship between gender and grade. For comparison of the effects of age on grade, and sales year on grade, a Kruskal-Wallis test was conducted. A value of p 0.05 was considered significant. A total of 858 horses were examined out of 4149 offered for sale; there were 57.58% colts and 42.42% fillies (mean age of 18.1 months). The annual percentage for grade 1 was 84.04% ± 9.98%, for grade 2: 14.49% ± 10.69%, for grade 3: 0.71% ± 0.57% and for grade 4: 0.76% ± 0.94%. There were no other significant findings. The exclusive nature of the sale and the increasing proclivity for pre-sale scoping may have skewed the results. This study shows that RLN grade incidences in TB yearlings at public auctions in South Africa are as follows: grade 1: 84.04%, grade 2: 14.49%, grade 3: 0.71% and grade 4: 0.76%. The results were similar to that of an adult population of horses examined in South Africa in a previous study.
Publication Date: 2020-04-20 PubMed ID: 32370531PubMed Central: PMC7203182DOI: 10.4102/jsava.v91i0.2013Google Scholar: Lookup
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  • Journal Article

Summary

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The research article is a study on the prevalence of recurrent laryngeal neuropathy (RLN), a horse throat condition, in thoroughbred yearlings sold at public auctions in South Africa between 2013 and 2019.

Study Overview and Aim

In this study, researchers conducted a retrospective analysis to understand how common RLN is in thoroughbred yearlings being auctioned in South Africa’s premier sales. The focus was on RLN because it’s a common cause of sale cancellations, which can be problematic for sellers and buyers alike.

  • Endoscopic examinations of the upper respiratory tract were used to determine the RLN grade using Rakestraw’s 4-point system.
  • The study covered buyer-requested endoscopic examinations between 2013 and 2019.
  • The results were then compared to previous studies on the topic.

Methodology

Medthodology used in the study included statistical tests and grouping of the horses to check the influence of factors like gender and age on the RLN grading.

  • Fisher’s exact test was used to determine if there was a relationship between gender and RLN grade.
  • Kruskal-Wallis test helped examine the effects of age and sales year on the RLN grade.
  • A total of 858 horses were examined, comprising 57.58% colts and 42.42% fillies with an average age of 18.1 months.

Results and Significance

The research revealed the grade-wise RLN prevalence as follows: grade 1: 84.04%, grade 2: 14.49%, grade 3: 0.71%, and grade 4: 0.76%.

  • No other significant findings were documented in this study.
  • The data indicated that the results might be skewed due to the exclusive nature of the sale and the growing trend for pre-sale scoping.
  • The study’s findings were found to be similar to those of earlier research on an adult population of horses examined in South Africa.

These results provide valuable insights into the state of laryngeal health in thoroughbred yearlings coming to market, thus informing future studies and potential breeders’ decisions.

Cite This Article

APA
Miller SM. (2020). Endoscopic recurrent laryngeal neuropathy grade prevalence in a sample of thoroughbred yearlings at public auction in South Africa (2013-2019). J S Afr Vet Assoc, 91, e1-e5. https://doi.org/10.4102/jsava.v91i0.2013

Publication

ISSN: 2224-9435
NlmUniqueID: 7503122
Country: South Africa
Language: English
Volume: 91
Pages: e1-e5
PII: 2013

Researcher Affiliations

Miller, Sean M
  • Summerveld Equine Hospital, Summerveld. sean@drummondtor.co.za.

MeSH Terms

  • Animals
  • Endoscopy / veterinary
  • Female
  • Horse Diseases / epidemiology
  • Horses
  • Male
  • Prevalence
  • Recurrent Laryngeal Nerve Injuries / epidemiology
  • Recurrent Laryngeal Nerve Injuries / veterinary
  • Retrospective Studies
  • South Africa / epidemiology

Conflict of Interest Statement

The author declares that no competing interests exist.

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Citations

This article has been cited 1 times.
  1. Ahern BJ, Sole A, de Klerk K, Hogg LR, Vallance SA, Bertin FR, Franklin SH. Evaluation of postsale endoscopy as a predictor of future racing performance in an Australian thoroughbred yearling population.. Aust Vet J 2022 Jun;100(6):254-260.
    doi: 10.1111/avj.13155pubmed: 35191021google scholar: lookup