Exercise‐induced pulmonary haemorrhage impairs racing performance in Thoroughbred racehorses

Abstract

SummaryReasons for performing study: Exercise-induced pulmonary haemorrhage (EIPH) occurs commonly in Thoroughbred racehorses worldwide. While EIPH is believed to be an important cause of impaired performance in these horses, there is limited evidence from sufficiently powered studies to evaluate this association. Objectives: To evaluate whether EIPH is associated with finishing position, distance finished behind race winners and differences in race earning among Thoroughbred horses racing in South Africa. Study design: Prospective cross-sectional study. Methods: One thousand Thoroughbred horses racing in South Africa were enrolled prior to a single race and underwent tracheobronchoscopic examination within 2 h of racing. Three observers, blinded to the horses' identity and race performance, independently evaluated EIPH occurrence and severity using video recordings of the examination. Data were analysed using multivariable logistic and linear regression while controlling for important horse and race factors as potential confounding variables. Results: Overall, 68% of horses had evidence of EIPH (grade ≥1). Horses without evidence of EIPH (severity grade 0), when compared with horses with any evidence of EIPH (grade ≥1), were >2 times more likely to win races (odds ratio = 2.3; 95% confidence interval 1.4-3.7; P = 0.001), finished an average of one length ahead of horses with EIPH (P = 0.03), and were 2.5 times more likely to be in the highest decile in race earnings (odds ratio = 2.5, 95% CI 1.5-4.1, P<0.001). However, no association was identified regarding finishing in the top 3 positions or earning money when analysed as a continuous variable or analysed as any winnings vs. none. Conclusions: Exercise-induced pulmonary haemorrhage was associated with impaired performance in Thoroughbred racehorses not medicated with furosemide and not using nasal dilator strips. These findings provide strong corroboration of previous research indicating that the occurrence of EIPH has a major impact on the ability of Thoroughbred racehorses to compete successfully as elite athletes.

Tracheobronchoscopic Assessment of Exercise‐Induced Pulmonary Hemorrhage and Airway Inflammation in Barrel Racing Horses

“…This study describes the prevalence of EIPH (45.3%) and TMA (99.3%) in a sample population of barrel racing horses under normal racing conditions in Alberta. The prevalence of EIPH detected in this study is high; however, it was lower than the reported prevalence of EIPH (68 and 55%) in large‐scale Thoroughbred racehorse studies . The physiological adaptations of barrel racing horses are likely similar to those of racehorses, so it is not surprising that there is also a high prevalence of EIPH among barrel racers.…”

Efficacy Of First Time Furosemide Use In Thoroughbred Racehorses In Brazil

“…In comparison, EIPH positive horses not receiving furosemide showed either an increase or no change in bleeding grades in two consecutive endoscopies. It has been postulated that EIPH reduced athletic performance overtime 6,7 and there is a welfare concern involving the occurrence of EIPH and the lack of treatment for the condition. Furosemide is the only approved pre-competition drug administered to EIPH positive racehorses in most racing jurisdictions making it essential that its mode of action and effects are studied in detail.…”

Bronchoalveolar lavage in the diagnosis of respiratory diseases in horses

“…Індукована навантаженням легенева крово теча (EIPH) діагностується найчасті-ше у спор тивних коней, які піддаються ін-тенсивному тренуванню, а також у тварин за важкої ліво шлуночкової серцевої недостат-ності [24,36].…”