Validation of a Rapid Bronchoalveolar Lavage Fluid Colorimetric Evaluation for Assessing the Severity of Exercise-Induced Pulmonary Hemorrhage in Horses in Field Conditions.

This study aims to validate a new rapid method for assessing the severity of exercise-induced pulmonary hemorrhage (EIPH) in horses through colorimetric evaluation of bronchoalveolar lavage fluid (BALF), rather than traditional laboratory-based evaluation of erythrocytes count.

Research objectives and approach

• The researchers aimed at establishing a more practical, reliable, and rapid method for evaluating horse EIPH.
• The study was exploratory in nature and was conducted to validate a color chart method with five shades of red for assessing the severity of EIPH.
• The potential effectiveness of the color chart was first assessed in a controlled environment using known BALF samples, before being validated in real-world situations, specifically at two barrel racing events.

Methodology

• The study was conducted in two stages.
• In the initial phase, they used ten sets of BALF samples with known erythrocyte counts.
• These samples were shown to two groups of 18 observers who independently matched the color of the BALF to one of the shades of red displayed on a smartphone screen.
• In the second phase, the team collected 63 BALF samples from 21 horses during real-life barrel racing events and assessed their color based on the chart.

Results

• The interobserver and intra-observer agreement regarding colors were > 0.9, indicating good consistency between observers.
• EIPH was diagnosed in 39 of the 63 sampled horses based on color detection.
• The conclusion showed that the number of erythrocytes in the BALF was related to the color of the BALF, confirming that colorimetric evaluation of BALF can be a practical and reliable method for rapid postexercise assessment of horse EIPH.

Implications

• The findings of this study open the possibility for a quick and reliable assessment of EIPH even in field conditions and without the need for costly and time-consuming laboratory analyses.
• This might improve the management of horses showing signs of EIPH during or after exercise thereby promoting their health and performance.