Compared to humans, horses lose much more electrolytes through sweat. That is why it is important to keep a close eye on the electrolyte balance after heavy training or during multi-day competitions.
The temperature at which an horse feels most comfortable is between -5 and 15 degrees (this is also called the thermoneutral zone). You can imagine that when the temperature rises above 15 degrees, a horse has to make more effort to maintain his body temperature, especially when he also has to make an effort. By sweating, the horse loses its excess heat. But what does sweat consist of? Sweat consists of water and body salts also called electrolytes.