Evaluation of race distance, track surface and season of the year on exercise-induced pulmonary haemorrhage in flat racing thoroughbreds in Brazil.

This Brazilian research studied the factors affecting Exercise-Induced Pulmonary Haemorrhage (EIPH) in thoroughbreds horses and the impact of pre-race administration of frusemide (FUR), highlighting the need for further studies to enhance understanding and determine the role of FUR, as a majority of horses remained EIPH positive despite its usage.

Introduction

• This study was undertaken to analyze the risk factors of Exercise-Induced Pulmonary Haemorrhage (EIPH) in Brazil’s horse racing community, focusing particularly on thoroughbred racehorses.
• This research is a significant contribution as no prior study has been conducted with such a population in Brazil, which is one of the few countries that approves the use of FUR as a pre-race medication for bleeders (horses that are susceptible to EIPH).

Objective

• The aim of this study was to assess the factors, such as race distance, track surface, going, and season of the year, that influence the recurrence and severity of EIPH and its impact on the finishing position of the horses.

Methods

• Data from 2118 post-race respiratory endoscopies performed on 1003 individual horses were recorded and analyzed.
• All horses in the study were certified bleeders and were given FUR prior to each race.
• Data was evaluated using ordinary logistic regression and multiple logistic regression.

Results

• Findings point out that factors such as race distance, season of the year, and track surface significantly affect EIPH recurrence.
• A large majority (62%) of horses continued to exhibit some degree of bleeding despite the use of FUR.

Conclusions

• Horses that remained EIPH positive despite the use of FUR, generally did not place in races. On the other hand, horses showing significant reduction in bleeding and became EIPH negative after FUR administration often finished in top positions.
• The severity pattern of EIPH in horses with multiple endoscopies wasn’t possible to determine and warrants further research for a better understanding of the syndrome and its impact on racehorse performance.
• The study gave a clearer understanding of FUR use in Brazilian racehorses and indicated a performance improvement among bleeders administered with FUR.
• The high proportion of horses continuing to be EIPH positive despite FUR use, calls for the scientific community to seek better ways to prevent or reduce this syndrome.