A Comparison of Five Cooling Methods in Hot and Humid Environments in Thoroughbred Horses.

The research investigates the best methods for cooling horses after strenuous exercise in hot and humid conditions, concluding that continually showering the animals with running tap water is the most effective way of reducing their core body temperature.

Objective of the Research

The main goal of the study was to identify the most effective cooling method for preventing exertional heat illness in horses after they engage in heavy physical exercise in hot and humid environments. The researchers tested the hypothesis stating that continuous application of running water proves to be the best technique to bring down the core temperature in horses.

Methods of the Research

• Five Thoroughbred horses were exercised on a treadmill under a wet-bulb globe temperature of 31.8 ± 0.1°C until their pulmonary artery temperature reached 42°C.
• The researchers measured the time taken for the pulmonary artery temperature to drop back to below 39°C (noted as ‘t’) and the horses’ rectal temperature 30 minutes after the onset of cooling.
• They compared these times across five cooling methods: walking without additional cooling (CONT); walking with fans producing an air current of 3.0 m/s (FAN); walking with intermittent application of 10°C cold water with (ICW + SCRAPE) or without scraping off excess water (ICW); and being stationary while experiencing a continuous flow of 26°C tap water from shower hoses (STW).

Results of the Research

• The shortest ‘t’ was produced by the shower method (STW), suggesting it’s the quickest way to bring a horse’s temperature down after exercise (P < .001).
• The study found that using intermittent cold water with scraping (ICW + SCRAPE) tended to take longer to cool the horses compared to without scraping (ICW – P = .06), however, both methods were significantly quicker than the fan and control methods (FAN and CONT – P < .001).
• The fan method reduced the temperature faster than the control method, but the difference was not statistically significant (P = .06).
• All cooling methods proved more effective at reducing rectal temperatures 30 minutes post-cooling onset than the control (CONT).
• The lowest temperature was observed with the showering method, and no significant differences were found between the fan and intermittent cold-water methods.

Conclusion of the Research

The research supported the hypothesis that showering with tap water is the ideal method to decrease core temperature in horses following strenuous exercise in hot and humid conditions. The researchers recommended this method as the most effective way of preventing exertional heat illness in horses.