Effects of different volumes of autologous blood instilled into the airways of horses on pulmonary function during treadmill exercise.

This research investigates the impact of different volumes of autologous blood (the horse’s own blood) instilled into the lungs, on the performance and pulmonary function of race horses during high-intensity exercise. The study found that unilateral instillation of up to 100 ml of autologous blood into the horse’s airways does not significantly impair the horse’s pulmonary function, breathing mechanics, or athletic performance.

Study Objective and Design

• The aim of the study was to ascertain the minimum volume of autologous blood that, when introduced into the horse’s airways, will significantly affect the creature’s performance and lung function during exercise.
• The study was carried out using six thoroughbred horses which underwent two bouts of exercises on each of four treatment test days.
• Each exercise session included a two-minute warm-up stage followed by running equivalent to the horse’s 115% maximum oxygen volume until the horse was exhausted.
• The second run on each test day included treatment with either no intervention (control) or 25, 50, or 100 ml of autologous blood instilled into the right side airways.

Methods and Measurements Taken

• In each exercise bout, arterial and mixed venous blood samples were obtained, and oxygen uptake (VO2), carbon dioxide output (VCO2), and breathing mechanics were measured.
• The procedure for the first run of each test day was without treatment. This functioned as a baseline for comparison with the other runs receiving different treatment protocols.

Key Findings

• The researchers found that unilateral instillation of up to 100 ml of a horse’s own blood into their airways does not significantly affect pulmonary function, breathing mechanics, or performance during intense exercise.
• This observation suggests that, up to the limits tested in this study, pulmonary bleeding likely induced by intense exertion does not markedly impact the horse’s racing performance.

Implication of the Results

• The study’s outcomes may be crucial in assessing the impact of exercise-induced pulmonary haemorrhage on racing performance, a common concern in the equestrian sports community.
• Although this study provides valuable insights, further research may be required to establish clearer guidelines on the limits and implications of exercise-induced pulmonary bleeding in equine athletes.