EIPH: postrace endoscopic evaluation of Standardbreds and Thoroughbreds.

The research investigates the incidence and severity of exercise-induced pulmonary haemorrhage (EIPH) among two horse breeds used for racing, Thoroughbreds and Standardbreds. It also explores whether the use of frusemide and the breed type impacts EIPH. The study reveals that most horses exhibit EIPH after races, but neither the breed of the horse nor administration of frusemide appears to influence EIPH incidence or severity.

Objective of the Study

• The primary objective of the study was to identify the rate and severity of exercise-induced pulmonary haemorrhage (EIPH) in Thoroughbreds (TB) and Standardbreds (STD), the two most commonly raced horse breeds.
• The secondary objective was to explore the potential influence of breed (or running gait) and frusemide administration on the incidence of EIPH.

Methodology

• The researchers used a semi-quantitative measuring device to rate the incidence of blood within the trachea after races. This 5-point system categorized the cases with zero when no blood was found and numbers 1-4 assigned for increasing amounts of blood.
• Both Thoroughbreds and Standardbreds were inspected, with or without the application of frusemide before races.
• The frequency of endoscopic assessments varied, with some horses examined once, others twice, while some others were studied three or more times.

Findings

• Approximately 75% of the postrace endoscopic examinations showed blood scores of 1, 2, 3, or 4, irrespective of frusemide administration or the breed of the horse.
• For horses examined twice, the likelihood of finding blood scores of 1 or more in either of the assessments increased to around 95%.
• All horses that underwent three or more endoscopic evaluations had blood scores of 1 or higher following one or more races, regardless of the breed or frusemide administration.
• There were no significant differences in the average blood scores between races involving Thoroughbreds and Standardbreds, with or without the use of frusemide.

Conclusion

• The research concludes that a large proportion of racing horses suffer from EIPH, as demonstrated by the presence of blood in the trachea after competitions.
• However, critical factors, such as the breed of a horse or use of frusemide, do not appear to influence the incidence or severity of EIPH. Therefore, further research is necessary to identify other potential factors affecting the condition.