Postoperative race performance is not correlated with degree of surgical abduction after laryngoplasty in National Hunt Thoroughbred racehorses.

The research article investigates the relationship between the extent of surgical arytenoid cartilage abduction after laryngoplasty (a surgical procedure to correct laryngeal paralysis) and the subsequent racing performance of National Hunt Thoroughbred racehorses.

Research Methods

• The study involved a case series of 68 National Hunt Thoroughbred racehorses that had undergone laryngoplasty paired with ventriculocordectomy.
• Researchers observed the degree of arytenoid cartilage abduction (retraction of the arytenoid cartilages, part of the larynx) following the surgery after one day, six days, and six weeks.
• To assess the correlation between the degree of arytenoid abduction and the subsequent racing performance, race records were analyzed. This included factors such as return to racing after the operation, total earnings in the five races immediately following the operation, and the lifetime number of starts post-operation.

Research Findings

• The median postoperative arytenoid abduction was noted to be grade 2 on day 1, reducing to grade 3 by 6 weeks. This implies that the degree of cartilage abduction tends to reduce over time post-surgery.
• It was found that horses with grade 1 abduction on day 1 were much more likely to lose abduction by day 6 post-surgery, compared to horses with grade 3 abduction on day 1. This indicates that the severity of initial abduction was linked to the likelihood of it deteriorating in the following days.
• However, no statistically significant correlation was found between the postoperative grade of arytenoid abduction at any stage, and factors such as earnings in the five races following surgery, likelihood of racing postoperatively, or total number of lifetime races started postoperatively.
• The limited number of horses with poor (grade 4 or 5) abduction in the study caveats the conclusions about the racing performance of such horses.

Research Conclusions

• The study concludes that horses with maximal (grade 1) surgical arytenoid abduction are significantly more prone to suffer a postoperative loss of abduction compared to those with grade 3 abduction.
• Importantly, the postoperative degree of arytenoid abduction does not significantly correlate with racing performance indicators.
• The research suggests that horses demonstrating moderate (grade 3) arytenoid abduction long-term after laryngoplasty can still potentially race successfully, providing a potential reassurance to surgeons.