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

Abstract

BackgroundPoor performance is often suspected to be associated with EIPH in barrel racing horses; however, there are no published reports of EIPH for this discipline. The prevalence of EIPH in barrel racing horses is also unknown.ObjectivesThis study was performed to determine the prevalence of EIPH and signs of airway inflammation in barrel racing horses under normal racing conditions in Alberta.AnimalsAbout 170 barrel racing horses.MethodsObservational cross‐sectional study. Tracheobronchoscopic examinations were performed at least 30 minutes postrace. Video recordings were scored off‐site independently by two observers for EIPH and tracheal mucus accumulation (TMA). Horses with an EIPH score ≥2 were not assessed for TMA. Interobserver agreement was calculated by weighted κ statistics. Run times, environmental variables, and clinical information were also recorded for analysis.Results77/170 (45.3%) of horses examined showed evidence of EIPH (grade ≥ 1). Interobserver agreement was 0.94. 140/141 (99.3%) of horses assessed for TMA showed evidence of tracheal mucus accumulation (grade ≥ 1) with 104/141 (73.8%) having a TMA score ≥ 2. Interobserver agreement was 0.73. A weak positive association was found between EIPH scores and average run speed, the presence of cough at rest reported by the riders, increased recovery time, exercise intolerance, and outdoor pattern.Conclusions and clinical importanceThe high prevalence of EIPH observed in the sampled population indicates that barrel racing induces substantial stress on the lungs. The presence of EIPH did not impact negatively on performance. Factors such as environmental dust and frequent traveling might have contributed to the high prevalence of TMA observed.

The association between exercise‐induced pulmonary haemorrhage and race‐day performance in Thoroughbred racehorses

“…In the current study, horses with EIPH grade 1 and 2 were significantly more likely to improve their position in the field over the final 400 m compared to horses with grade 0. In barrel racing horses, those with EIPH grade 4 were significantly faster than EIPH grade 0 animals when all race distances were considered together [16]. While it is highly improbable that EIPH confers an athletic advantage to these horses, the results warrant the use of secondary models comparing categorised groups of EIPH based upon severity.…”

Relationship between tracheobronchoscopic score and bronchoalveolar lavage red blood cell numbers in the diagnosis of exercise‐induced pulmonary hemorrhage in horses

“…The reported prevalence of EIPH based on TBE is highest in racing Thoroughbreds, with other strenuous athletic activities having lower rates of occurrence, including observed prevalences of 45% and 54% in barrel racers. This finding confirms the high prevalence of EIPH in horses after strenuous exercise of different types .…”

Clinical Approach to Commonly Encountered Problems

“…227,228 It is common in Thoroughbred and Standardbred racehorses and in other horses performing strenuous exercise, such as barrel racing horses. 227,228 It is common in Thoroughbred and Standardbred racehorses and in other horses performing strenuous exercise, such as barrel racing horses.…”