Risk Factors for Epistaxis in Thoroughbred Flat Races in Japan (2001-2020).
Authors: Sugiyama Fumi, Takahashi Yuji, Nomura Motoi, Ebisuda Yusaku, Mukai Kazutaka, Yoshida Toshinobu
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Risk Factors for Exercise-Induced Pulmonary Haemorrhage in Japanese Thoroughbreds Exercise-induced pulmonary haemorrhage (EIPH) remains a significant welfare concern in flat racing, yet geographic and individual risk factors remain poorly characterised in Asian racing populations. Sugiyama and colleagues analysed two decades of Japanese racing records (2001–2020), examining endoscopically confirmed epistaxis across 475,709 race starts using multivariable logistic regression to identify independent risk factors. Beyond previously documented associations—cooler ambient temperatures, softer track conditions, shorter distances (≤1400 m), older horses, and mares or geldings—two striking findings emerged: each 20 kg increase in body weight elevated epistaxis risk by 33% (OR 1.33), and certain racecourses showed dramatically elevated incidence, with Sapporo, Hakodate and Kokura displaying 4.7–4.1 times greater risk than the reference course at Kyoto. For practitioners, these data suggest that venue-specific environmental or management factors warrant investigation, whilst body weight management may represent a modifiable risk variable worthy of individual assessment alongside traditional conditioning and track preparation protocols. The integration of racecourse-level epidemiology into training decisions could refine prevention strategies and support evidence-based interventions to reduce EIPH incidence across flat racing operations.
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Practical Takeaways
- •Heavier horses competing in flat racing face substantially higher epistaxis risk; veterinary clearance and pre-race assessment should account for body weight as a modifiable risk factor
- •Environmental and track-specific factors (certain venues, cooler temperatures, softer going) present identifiable epistaxis risk situations where enhanced surveillance and preventive protocols may be warranted
- •Older horses, females, and geldings competing over shorter distances in poor conditions represent the highest-risk population for epistaxis events on race day
Key Findings
- •Epistaxis occurred in 616 of 475,709 race starts (1.30 per 1000 starts; 95% CI, 1.20-1.40) in Japanese flat racing over 20 years
- •Body weight per 20 kg increase was significantly associated with epistaxis risk (OR 1.33; 95% CI, 1.25-1.41)
- •Specific racecourses showed elevated epistaxis risk compared to reference (Sapporo OR 4.74, Hakodate OR 4.66, Kokura OR 4.14 versus Kyoto)
- •Lower ambient temperature, soft surface conditions, shorter racing distances (≤1400 m), increasing age, and female/gelding sex were significantly associated with epistaxis