A function for guttural pouches in the horse.

This research uncovers the unique role of guttural pouches in horses in cooling their blood and, in turn, protecting their brains from overheating during exercise.

Objective of the Research

• This study was conducted to shed light on how horses, as athletic animals, regulate their body temperature, particularly the heat of their brains, during strenuous activities. Prior to the research, this remained unclear as horses do not seemingly possess the usual thermoregulatory devices seen in other animal species.

Unique Anatomical Feature

• The research highlighted the unique anatomical configuration of horses’ internal carotid arteries which supply blood to the brain. Unlike in other animals, these arteries in horses are enclosed by a pair of air-filled guttural pouches. This unique arrangement piqued the interest of researchers and they sought to find out whether these pouches contribute to the cooling mechanism of the horse’s body.

Key Findings

• The study revealed that horses utilize their guttural pouches to cool their carotid arteries during physical exertion. The air-filled pouches appear to act as temperature-moderating systems, effectively cooling the blood circulating to the brain through the carotid arteries.
• By reducing the temperature of the blood going through them, the guttural pouches help to guard the horse’s brain from overheating, a condition (hyperthermia) which can cause irreversible damage to the organ.

Implication of the Study

• This finding is significant as it uncovers a unique thermoregulatory mechanism in horses which allows them to engage in strenuous physical activities without damaging their brains due to overheating. This knowledge can prove useful in managing the health and performance of athletic horses.