Why Are You Blanketing Your Horse This Winter?

Horses living in northern climates are often no strangers to snuggly blankets. Approximately half of all North American horses and more than 80% of horses in Sweden and Norway are blanketed, according to industry surveys.

“Blankets are used on horses primarily to protect them from cold, wind, rain or snow, and to help keep them clean,” said Katie Young, Ph.D., a nutritionist for Kentucky Equine Research.

Horses may not need blankets in the winter to keep warm as long as they have access to some sort of shelter and can remain dry. In these situations, horses are usually capable of regulating their internal temperature without the assistance of a blanket.

Some strategies horses use to thermoregulate include:

• Shivering to generate heat;
• Constricting blood vessels near the skin to minimize heat loss;
• Piloerection, in which the hairs stand on end to allow air to nestle between the hairs and insulate the horse;
• Facing away from the wind or standing in a certain direction to maximize solar radiation; and
• Increasing fiber consumption, as hindgut fermentation is a heat-producing process.

“Horses may also thermoregulate by altering hair length or diameter, which is why some owners prevent their horses from growing a longer, heavier winter hair coat through a system of blanketing based on temperature,” said Young.

According to University of Wisconsin researchers, only anecdotal evidence supports this last hypothesis. To better understand the effect of blanketing on hair coat length and diameter, 16 mature horses were either blanketed or left unblanketed between October 2019 and March 2020. To measure hair length and diameter, hair coat samples were collected monthly from the hindquarters and the side of the neck not covered with mane.

Regardless of blanketing, hindquarter and neck hair length was longest and had the greatest diameter in January and February and were shortest in October and March. However, blanketed horses did indeed have significantly shorter neck hair length compared to unblanketed horses in both January and February.

“This shows that blanketing alters hair coat growth, with shorter, thinner hair observed in blanketed horses in frigid weather. Those changes, however, were not long-lasting, as the hair length and diameter returned to baseline values by March,” summarized Young.

Whether a horse is blanketed or not, help ensure healthy skin condition and optimal hair coat by providing proper nutrition.

“Along with a well-balanced diet, horse owners can feed Bio-Bloom PS (Bio-Bloom HF in Australia), a supplement designed to support healthy hair and hoof growth, and help produce a soft, shiny coat,” relayed Young.

^*DeBoer, M., A. Konop, B. Fisher, and B. Fisher. 2023. Changes in hair coat length and diameter in blanketed and nonblanketed adult horses in the winter. Journal of Equine Veterinary Science 120:104191.