Better late than never. Proper year-round care will help your horse be in the best condition to face the stresses of winter and will minimize the number of health scares for you during the winter months. Horses should be dewormed every 60 days no matter what the season. Vaccinations for influenza and rhinopneumonitis should be given well before the cold, wet weather of the fall and repeated every 90 days for horses constantly exposed to situations associated with these respiratory infections. Winter-specific stresses include but are not limited to wind, wet, cold, lack of exercise, and owner disinterest.
Horses can withstand temperatures well below freezing as long as it is sunny and the air is still.
The winter coat traps body heat next to the horse's skin. During cold temperatures, pilo erector muscles make the hair stand up which increases the coat's insulating potential. Wind separates the hairs, thereby breaking the heat seal which results in a great loss of body warmth. A wet horse loses body heat many times faster than a dry horse. In addition, wet hair tends to become plastered close to the horse's body, allowing no air insulation to exist.