What is the main effect of heat stress on a horse's body?

The main effect of heat stress on a horse's body is an internal temperature rise. When a horse experiences heat stress, particularly in high temperatures or during physical exertion, its body temperature increases as the horse works to maintain thermoregulation. This internal temperature elevation can lead to several physiological responses, including increased heart rate and respiratory rate, as the horse tries to dissipate heat through sweating and increased blood flow to the skin.

Understanding this concept is critical for horse care, especially during warm weather or periods of intense training. It emphasizes the importance of monitoring a horse’s condition and ensuring that they have adequate hydration and opportunities to cool down.