Those of us that live in Northern climes have felt it–the chilly, tingly, numbing feeling of ears, nose, fingers, or toes exposed too long to cold. If exposure to frigid temperatures continues, frostbite can occur.
Fortunately, Mother Nature has better provided for horses than for humans against the perils of frostbite. Explained Janice Sojka, VMD, associate professor of large animal medicine, Purdue University, “Humans evolved as tropical animals. We spread out beyond a tropical environment because we’ve succeeded in taking our tropical environment with us: That’s why we have central heating! But horses evolved as temperate animals, and are actually more comfortable in cold temperatures than in warm. One source states the horse’s neutral zone–the temperature where the animal is most comfortable and is not expending any energy to keep itself cool or warm–is between 20 and 40 degrees Fahrenheit.”
That’s why healthy horses, when left to their own devices, don’t suffer the same discomforts as humans when exposed to chilling temperatures.
Additionally, although mammals protect their vital organs against severe cold by shunting blood away from the extremities to the core, leaving the extremities vulnerable to frostbite, horses can shunt a lot of blood away from their feet and still have a very functional foot.
“We don’t understand blood shunting of the horses’ feet very well,” says Andris J. Kaneps, DVM, PhD, Diplomate, ACVS, an assistant professor of large animal surgery, Oregon State University. “But there is some type of protective role to the feet in cold weather