Exercise-induced pulmonary hemorrhage in racing thoroughbreds: a preliminary study

Area of Science:

• Equine Sports Medicine
• Veterinary Pulmonology
• Equine Exercise Physiology

Background:

• Exercise-induced pulmonary hemorrhage (EIPH) is a common condition in racehorses.
• Understanding the prevalence and contributing factors of EIPH is crucial for equine athlete welfare and performance.

Purpose of the Study:

• To determine the frequency of EIPH in Thoroughbred racehorses shortly after racing.
• To investigate potential correlations between EIPH and factors such as age, sex, and finishing position.
• To assess the efficacy of furosemide treatment for EIPH.

Main Methods:

• Flexible fiberoptic endoscopy was used to examine 235 Thoroughbred racehorses within 2 hours of racing.
• Statistical analysis was performed on data from 191 horses that finished in the top three positions.
• Upper respiratory tract abnormalities were also noted.

Main Results:

• EIPH was detected in 103 out of 235 horses (43.8%), with 0.8% experiencing epistaxis.
• No significant relationship was found between EIPH and age, sex, or finishing position in top-placing horses.
• A trend suggested increased EIPH frequency in horses aged 5 years and older.
• Furosemide treatment did not appear to prevent EIPH, as 30 of 56 treated horses showed signs of hemorrhage.
• Eight percent of horses exhibited upper respiratory tract abnormalities.

Conclusions:

• EIPH is highly prevalent in Thoroughbred racehorses post-exercise.
• Age may be a contributing factor to EIPH, possibly due to chronic pulmonary damage.
• The effectiveness of furosemide in preventing EIPH warrants further investigation.
• Upper airway abnormalities are also a concern in this population.