What stimulates the secretion of sweat in horses?

Sweating in horses is primarily facilitated by the apocrine glands, which play a crucial role in the thermoregulatory process of the animal. These glands are stimulated by the release of epinephrine, which is a hormone important for the "fight or flight" response. During stressful situations or intense exercise, epinephrine is released into the bloodstream, leading to increased heart rate, improved blood flow to muscles, and activation of the apocrine glands, thereby promoting sweat production.

The combination of epinephrine and the function of the apocrine glands is essential because it allows the horse to maintain a stable body temperature through evaporative cooling. As the sweat evaporates from the skin, it aids in dissipating heat generated during physical activity.

Understanding this relationship between apocrine glands and epinephrine helps in recognizing how horses regulate their body temperature during exertion and manage stress.