Horses and Ponies grow two coats per year. The summer coat is short and sleek to allow efficient heat loss in hot weather, when protection against cold and wet is not so critical; the winter coat is longer and thicker (because the longer hairs overlap), and protect the animal against wind by trapping a layer of warm air next to the body to insulate it, and against the wet.
In native, cob and cold-blood breeds, the winter has large numbers of longer hairs to help water drain off more efficiently. Such breeds also have long hair, called feathering, around the fetlocks to help protect against mud and wet.
Some pony breeds, particularly those from northern climates, have a double coat in winter, with long outer hairs to keep out the wind and rain, and shorter under-hairs for extra warmth and protection. Their manes and tails are often wiry and thick for the same reason.
The skin of all breeds produces natural grease to help lubricate the skin and hair and provide protection against the rain and, to a very small extent, flies. The skin itself has an outer layer of dead tissue which is gradually shed as fresh cells come to the surface to replace it. The outer layer ensures that the skin is protected and is not over- sensitive. The shed flakes are seen in an ungroomed animal as dandruff.
In the natural state, this grease and dandruff does not become excessive, and is left on the skins coats of domesticated horses that spend a lot of time in pasture, to help give protection. However, stabled animals have grease and dandruff removed by body brushing, to ensure that the skin is clean and stimulated, and able to work efficiently at excreting, through sweating, the waste products of exercise and a concentrated diet.
Horses groom themselves in the wild in a rough and ready way. Mutual grooming, where horses go along each other's back with the top teeth, helps dislodge and discourage parasites and is enjoyed by all. Horses also stimulate their skins by rubbing against hedges and trees, and by rolling.
CASTING THE COAT
Horses cast (change or molt) Their coats in spring and autumn and tend to look a little rough, particularly in autumn. There is an old saying that no horse looks its best at blackberry time, and it's true. The hair comes out at intervals-the horse will cast a little and grow a little, cast a little and grow a little, until after a month or two the new coat will be complete, or "set".
CLIPPING THE COAT
Clipping helps prevent excessive sweating during winter. The type of clip depends on the horse's workload, constitution, and how you keep it. The hunter clip (top) is only for for very hard working stabled animal. The blanket clip (middle) suits moderate to hard-working horses stabled or kept on the combined system. The trace clip (bottom) is suitable for horses or hardy native ponies doing light work, and kept out.