Exercise-induced pulmonary haemorrhage in Thoroughbred racehorses: a longitudinal study.
Authors: Crispe E J, Secombe C J, Perera D I, Manderson A A, Turlach B A, Lester G D
Journal: Equine veterinary journal
Summary
# Exercise-Induced Pulmonary Haemorrhage in Racehorses: Progressive but Modifiable Exercise-induced pulmonary haemorrhage (EIPH) is common in racing Thoroughbreds, but whether tracheobronchoscopic evidence of bleeding worsens predictably throughout a horse's career has remained unclear. Crispe and colleagues conducted a longitudinal analysis of 2,974 endoscopic examinations across 747 racehorses, with experienced observers grading haemorrhage severity on a 0–4 scale following racing efforts. Over 55% of examinations revealed blood in the airways, and whilst EIPH demonstrated mild progression during the first thirty career starts, several modifiable factors influenced whether horses moved to more severe grades: specifically, the interval between races, ambient temperature, and weight carried all significantly affected EIPH severity trajectory. The preceding examination score was strongly predictive of current findings, suggesting inherent individual susceptibility, yet the beneficial effect of spacing races and limiting preparation duration offers practitioners tangible management options for affected horses. Given these evidence-based parameters, veterinarians and trainers should consider extended rest periods between competitions for horses with moderate to severe EIPH and monitor environmental conditions during peak racing seasons, whilst acknowledging that further investigation into temperature-related mechanisms is warranted.
Read the full abstract on PubMed
Practical Takeaways
- •Spacing races and limiting the duration of racing preparations may help reduce EIPH severity in horses with moderate to severe disease
- •EIPH tends to persist and worsen gradually over a racehorse's career; early detection and management are important
- •Consider ambient temperature as a variable that may influence EIPH severity—further research is needed to define optimal racing conditions
Key Findings
- •Blood was detected in 55.6% of all tracheobronchoscopic examinations across 2,974 procedures
- •Tracheobronchoscopic EIPH showed mild progression over the first 30 career starts
- •Previous EIPH score was significantly associated with current EIPH score, indicating persistence of the condition
- •Days since last racing, ambient temperature, and weight carried were significant factors associated with changes in EIPH severity between examinations