Q. Some people say you should put warm blankets on horses in the wintertime, and some people say you shouldn’t because then they won’t grow heavy coats. What do you say?
A. I live way up in frigid northern Minnesota where it can get down to -40F, and I rarely blanket any of my horses. In fact, the only time I will blanket a horse is if (s)he is ill, badly injured, very thin, or losing weight rapidly. It is also necessary to blanket those animals who have relocated from a warm climate to a cold one with inadequate time to grow a winter coat before the onset of cold weather. Of course, horses who are clipped off their winter coats also require full blanketing in cold weather.
I don’t believe blankets inhibit the growth of a full winter coat as much as they flatten a coat that already exists. The coat needs to stay fluffy to trap as much insulating air as possible.
Other considerations before blanketing are the temperament and training of the horse to wear a blanket safely, proper fit, weatherproof materials if the blanket is to be worn outside, and adequate supervision to assure that the horse won’t become entangled in a blanket that slips out of position.
All in all, I don’t recommend blanketing under normal circumstances. Horses are very well suited to cold climate survival when given adequate shelter and nourishment.