Long term follow up of medical treatment and race performance following laryngoplasty and ventriculectomy in 176 Thoroughbred racehorses in Australia

 

AJ Williamsona*, RM Greerb and N Kannegieterc

 

From the Faculty of Veterinary Science. University of Melbourne, Melbourne, Victoria, Australiaa

From the School of Veterinary Science, University of Queensland, Gatton, Queensland, Australiab

From Kannegieter Equine Specialistsc


Abstract

Objective       To evaluate short and long term management and long term race results of Thoroughbred racehorses following combined left laryngoplasty and left ventriculectomy under Australian conditions.

 

Design        Retrospective case series conducted between August 1999 and December 2009.

 

Procedure      Case records and race results were evaluated for 176 Thoroughbred racehorses that underwent left sided laryngoplasty and left ventriculectomy performed by the same surgeon. Short and long term medical records were reviewed for Warwick Farm Equine Centre cases. Performance indices were compared between groups using the Wilcoxon rank sum test, or the Wilcoxon sign rank test for paired data.

 

Results           Following surgery, 79% (139/176) of horses raced, 59% (104/176) started more than five races and 44% (77/176) won a race. Raced horses performed better following surgery than unraced in terms of return to racing (86% Vs 65%), number of starts (median 7 Vs 4.5) and post-surgery earnings (median $4,727 Vs $100). Short-term complications occurred in 14% (8/58) of WFEC cases. During training in the post-operative period, 24% (9/37) required further endoscopy, with subsequent medication administration due to the presence of LRT inflammation and/or infection. Subjective medication requirement did not significantly influence evaluated race results. Two horses with severe nasal discharge of feed raced post-surgery.

 

Conclusion    Previously raced Thoroughbreds were significantly more likely to return to race, have more starts and higher earnings. Cases with medically managed post-operative LRT disease can race as effectively as those without.

 

Keywords

Horse, Australia, recurrent laryngeal neuropathy, laryngeal hemiplegia, roarer, laryngoplasty,