Almost never is there a genuine need for a horse in Missouri to wear a blanket. Horses are well-equipped to handle cold weather. Their thick winter coats provide them with a great deal of protection. The thick, long hair traps a lot of air near the skin, providing great insulation. Horses that commonly wear blankets are show horses for whom a long, thick haircoat is not appropriate. These horses either do not develop a thick, warm coat because of the blanketing, or they have the hair clipped off with a body clip. Once the horse starts wearing a blanket in the winter, it will likely have to be maintained for the winter. Blankets flatten the hair keeping it from trapping air near the skin. In addition, if they’re wearing the blanket and it gets wet, their coat is further compressed and even less effective at retaining heat.
Some horses with certain medical conditions do well to be blanketed in the winter. Some geriatric horses with Cushing’s disease need to be blanketed. Ironically, these horses develop an exceptionally long, thick winter haircoat, but often the hair needs to be clipped because they also tend to sweat excessively and inappropriately. Their long, thick hair is often soaking wet and matted close to the skin and then can provide little protection. They are best body clipped and blanketed.
Other horses which might need to be blanketed are those with very little body fat. These are malnourished horses, those with diseases which make it difficult for them to absorb food, or some very young horses. Because some breeds encourage having mares foal in January and February, some neonatal foals are born during the coldest weather. They may need to wear little foal blankets if they have difficulty maintaining their body temperature in the cold weather (note excessive shivering).