Tidal breathing flow-volume loop analysis as a test of pulmonary function in exercising horses.

The research investigates the effectiveness of Tidal Breathing Flow-Volume Loops (TBFVL) in evaluating lung function in actively exercising horses. The study includes Standardbred horses and involves tests conducted before and after inducing lung disease, showing minimal differences in TBFVL results in cases of mild lung obstruction.

Understanding Tidal Breathing Flow-Volume Loops (TBFVL)

• Tidal Breathing Flow-Volume Loops (TBFVL) are graphics that depict the relationship between airflow rate and the tidal volume or the volume of air displaced between normal inhalation and exhalation, for each breath. Here tidal volume doesn’t refer to a tide of water, but rather the total volume of air that is inhaled or exhaled in normal respiration.
• These are used to evaluate lung function, providing a visual representation of how smoothly and efficiently air moves in and out of the lungs.

Research Process

• The research involved 6 Standardbred horses performing treadmill exercise. The horses exercised at speeds equivalent to 75% and 100% of their maximum heart rate.
• The researchers collected TBFVL data from each horse both before and after inducing allergic lung disease using a protein called ovalbumin, a common allergen used in similar studies.
• The ovalbumin-induced lung disease resulted in moderate obstructive lung disease in the horses while they were at rest, demonstrating a significant increase in pulmonary resistance.

Research Findings

• The researchers found minimal differences in the TBFVL shape and size indications between horses with airway obstructions and those without, while exercising at comparable speeds.
• This suggests that TBFVL may not be a reliable method for detecting or evaluating the degree of airway obstruction in horses during active exercise. The TBFVL readings seemed to stay relatively normal even when the horses had moderate obstructive lung disease.
• This could potentially be due to the increased breathing rates during exercise, which might counteract the effects of airway obstruction on the TBFVL readings.