Too many layers can cause the horse to sweat, then chill which lowers the horse's resistance by sapping the horse's energy. This is an open invitation for respiratory infections. Check for over-heating by slipping a hand under the blanket at the heart girth area. To allow perspiration to evaporate, choose a breathable blanket for your horse. If he lives outdoors, make sure it is waterproof and breathable.
Clipping allows a horse to be more easily worked, cooled out, and groomed in the winter months.
The first clip may occur in October and may need to be repeated five to six times throughout the winter and early spring. This will depend on the horse's work, blanketing, and housing. Vigorously currying a winter coat can disrupt the natural protective layer of oils which is essential for protection from moisture. After riding, rub the coat dry with a cloth or gunny sack or allow the horse to roll in sand or dry snow. Winter presents unique problems for the horse.