Effect of environmental temperature and relative humidity on breathing pattern and heart rate in ponies during and after standardised exercise.

This study aims to understand how different weather conditions, including temperature and humidity, affect the breathing patterns of ponies during and after standardized exercise. The findings indicate that while these conditions don’t meaningfully change the ponies’ breathing during rest or exercise, they may alter it during recovery, specifically in hot and humid weather.

Research Methodology

• The researchers conducted a preliminary study to examine the impact of atmospheric conditions on ponies’ breathing patterns.
• Five ponies, aged between three to five years old and weighted around 257 ± 9kg, underwent the study.
• A standardized procedure was used to measure the ponies’ respiratory airflow, tidal volume (the amount of air inhaled and exhaled normally), breathing frequency, minute volume (the total volume of air the ponies breathe in one minute), total pulmonary resistance, and heart rate.
• Measurements were recorded at rest, during a nine-minute period of treadmill exercise, and during a five-minute recovery period.
• The surrounding temperature and relative humidity were logged at each data collection time. Based on the summation of these readings, researchers divided the data into two groups: where the sum was less than 85, indicating cold and dry conditions, and where it was greater than 85, signifying hotter, humid conditions.

Results

• Results revealed no significant alteration in the ponies’ breathing patterns influenced by the ambient temperature and humidity, neither at rest nor during exercise.
• However, during the recovery phase, a significant increase in breathing rate was noted under hot and humid conditions. Additionally, a marked decrease in tidal volume and total pulmonary resistance was observed as compared to cold and dry conditions, while the minute volume remained steady.

Implications

• The results suggest that the recovery phase’s environmental conditions can influence a horse’s breathing pattern substantially, especially in hot and humid weather conditions.
• The findings indicate that in such conditions, the respiratory rate may not be a reliable indicator of a horse’s fitness level, necessitating further comprehensive pulmonary investigations for accurate fitness assessment.