What is the Most Efficient Way to Cool Down a Horse?

Veterinary

Health Care

A study carried out in Japan has compared 5 different techniques in cooling down a horse after intensive exercise.

The Study

Five Thoroughbreds were exercised on a treadmill at wet-bulb globe temperature of 31.8 ± 0.1°C until their pulmonary artery temperature reached 42°C. The time until the pulmonary artery temperature returned to <39°C (t₃₉) and the rectal temperature at 30 minutes after the onset of cooling were compared between five cooling methods in a 5 × 5 Latin square design.

This study was conducted between July and September in 2018 at Japan Racing Association’s Equine Research Institute.

The Methods to Cool

1. Walking
2. Fan with air current of 3.0 m/second
3. Intermittent cold water + scraped off. Repeated every 3 minutes
4. Intermittent cold water poured on the horse every 3 minutes NOT scraped off
5. Hosed down continuously for 30 minutes with room temperature (tap) water.

The Results

This study clearly demonstrated that showering horses continuously with tap water (at 26°C) was superior to the intermittent application of cold water (at 10°C) for cooling after exercising in hot and humid conditions. This was because a humid environment can limit evaporation, making it essential to enhance heat conduction.

The essential feature is not the water temperature or the use of scraping but that the horse is kept covered in water cooler than its body temperature over an extended period of time

Why?

Horses can’t cool down well by sweating in hot and humid weather, so they need other ways to lose heat.

Showering continuously with tap water was the fastest way to cool down the horse, reaching baseline body temperatures after only 6 minutes almost 5 times faster than the second fastest method, which was intermittently poring cold water onto a horse every 3 minutes.

This is because water cools the body better than air because it can transfer heat more effectively. As long as the water is cooler than the horse’s body temperature, it helps cool the horse down.

In this method, the horse’s skin stayed in contact with cooler water, which lowered its temperature through conduction.

Even if the water was colder in the other methods, it would stagnate the cooling affect as the water became closer to the bodies temperature, needing to continuously dump water on the horse to lower to baseline temperature.

Source

Takahashi, Y., Ohmura, H., Mukai, K., Shiose, T., & Takahashi, T. (2020). A comparison of five cooling methods in hot and humid environments in thoroughbred horses. Journal of Equine Veterinary Science, 91, 103130.

Text by The Data Driven Equestrian, edited by Eurodressage