Extreme weather does not phase horses—especially if they are well-fed and well-sheltered. Cold weather can still be stressful for horses, though. The degree to which horses can withstand cold varies by breed, age, body type, and shelter. Because of their tiny stature and thick winter coats, northern breeds such as Arabians and Norwegian Fjords are often better suited to withstand cold temperatures.
Horses' thick winter coats allow them to withstand rather high temperatures. If the weather is too severe, they may still experience weather stress. The wind chill effect is a major concern since it can significantly reduce perceived temperature by trapping air near the body.
Horses' ability to sweat off heat is also influenced by humidity. Horses sweat to generate a particular protein called latherin, which helps prevent the water on their skin from evaporating and cools them down. However, this mechanism may not function well in very humid situations (Eckersall et al., 1982).
Riding horses is best avoided when the combined temperature and humidity are higher than a particular level. A "heat index" is a useful tool for checking this, as it is a single value that represents both air temperature and relative humidity. Additional, more thorough measurements, such as AccuWeather's RealFeel, also account for factors including cloud cover, air movement, and solar radiation.
Since horses' bodies are larger than those of humans, they must radiate more heat per square inch of skin when the temperature rises. They are therefore more vulnerable to heat stress and may experience colic or even dehydration.
On the other hand, because of their thick winter coats, horses are better equipped to tolerate cold weather when the temperature drops. However, a number of variables, including as breed, age, physical condition, and shelter, affect this resilience.
A horse may become uncomfortable with the sudden drop in temperature very rapidly if they are not well insulated or do not have access to a three-sided shelter that keeps out wind and precipitation. Furthermore, horses may find it difficult to release their internal heat if the temperature decrease is combined with a wind chill factor, causing the perceived temperature to drop below freezing.
A horse's body temperature is impacted differently by snow and rain. A mechanism known as piloerection, which occurs when there is moisture present, causes the hairs on a horse's body to bristle and rise, keeping the animal warm. When rain or snow is present, this effect is lessened.
In addition to increasing the chance of injury, cold weather makes the footing more dangerous due to its tendency to become slick and frozen. Muddy footing can lead horses to lose their footing and fall, while ice and slushy footing can twist tendons and joints and produce foot bruises.
Instead of being hurried into a stall or turned out in the cold and immediately brought back inside, horses should be given time to acclimatise to a natural dip in temperature. Because of lowered metabolic rates, older horses and foals in particular may have trouble controlling their body temperature. You can add a mineral supplement like Zesterra or CattlActive to their diet to help them adjust to these changes.
