Every year as the days get shorter and temperatures drop horse owners wonder if they should blanket their horses. If they do blanket them, what weight of blanket? Do they need to go out and change the blankets several times a day as the temperature changes? Do these decisions change if the horse is clipped? Should the horse be clipped? Should arenas and barns be heated?
Horses like the cold
Most horse owners are quite aware that horses seem to prefer much cooler temperatures than they themselves do. Therefore deciding to blanket a horse just because people feel the need to wear sweaters and coats is obviously not the correct approach to deciding upon horse apparel.
One interesting study of clipped horses engaged in trotting races reported that horses seemed to prefer exercising in 12 to 19 degrees Celsius weather. Their performance declined outside this temperature range, but declined the most as temperatures went higher- the horses preferred 4 to 12 degrees over temperatures above 20 degrees. But they really liked the 12 to 19 degree zone. To those of us in Fahrenheit areas, this means that clipped horses are most comfortable exercising in 50 to 60 degree weather.
Unclipped horses are perfectly capable of surviving- and thriving- in temperatures down to -40 degrees. The most important factor isn't the temperature, whether they are blanketed or not, or whether they have shelter. No, it's the quality of the forage (hay) that they are fed. Good-quality hay can keep a horse warm regardless of exterior conditions.
Clipping makes a difference
Many people have observed that unclipped horses in a winter coat tend to sweat while just standing around in practically any weather. Throw a blanket over the top of that unclipped horse and you get a very uncomfortable, hot sweaty horse. It seems clear that unclipped horses don't need blankets. But maybe the clipped horse needs blankets? Should horses be clipped?
One study of three horses exercised them in sub-zero temperatures. The horses were exercised on an outdoor track. They were first exercised in an unclipped state for five days, and then they were exercised while clipped for five days. Once clipped, they were blanketed before and after exercise. The respiration rate, body temperature, skin temperature and amount of sweating were measured. Unclipped horses had elevated respiration rate, elevated body temperature, and measurable sweating after exercise in these very cold temperatures. Clipped horses had none of these, but they did suffer from cool skin temperatures on their legs at the beginning of the exercise period. The use of riding blankets corrected the cool skin temperatures.
In the sub-zero temperatures studied, the unclipped horses were clearly overheating during exercise. This study provides more support against ever blanketing unclipped horses- they are more than warm enough in their natural coats. It does, however, suggest that horses that are expected to work during the winter might be more comfortable if clipped and kept blanketed when not working.
Obviously the conclusion depends on the particular horse, the exact local weather conditions and what the horse is expected to do on a daily basis, but there seem to be several rules of thumb:
- unclipped horses don't need blankets regardless of how cold it is- they need good hay instead
- clipped horses need blankets in sub-zero temperatures
- clipped horses are more comfortable during exercise than unclipped horses