Winter to Summer Changes in a Horse's Coat and Color

A horse's coat grows longer and thicker in the winter as a protection against cold temperatures. Its fluffy hair acts as an insulating layer that retains the horse's body heat. In the spring, the horse sheds its coat and replaces it with a thinner and cooler one in preparation for the hot summer. Stimulating the shedding process in the spring will encourage a horse's healthy summer coat. A horse's color may change from a darker shade in the winter to a lighter hue in the summer.

  1. A Horse's Winter Coat

    • During the winter season, a horse has two different coats. At the onset of winter, the hair will be short and thick. In response to the progression of lower temperatures, the horse's hair becomes longer, fluffier and more erect. This enables the coat to trap pockets of warm air in between the hair and closest to the horse's body to keep it warm.

    Winter to Summer Changes

    • As the season changes to spring and summer and the days become longer and warmer, it stimulates the horse's body to shed its winter coat. Before shedding begins, the horse begins to grow its summer coat beneath its long winter hair in early spring. Generally, a horse will maintain its sleek summer coat until late fall, but this will depend upon how quickly autumn night temperatures begin to drop.

    Color Transformation

    • If a horse's winter undercoat is a different shade than its outer coat, its color transformation from winter to summer will be most noticeable. Seasonal color changes are most obvious in a bay horse because its undercoat is nearly black. As the horse sheds its winter coat, it will appear darker in the spring until later in the summer. A horse's coat will typically become lighter in the summer due to fading from the sun.

    Shedding

    • Each horse has its own individual shedding pattern, which typically begins with the chest and legs and follows with the armpits, flanks and belly. The horse's face, nose and loins shed last. Abnormal shedding patterns are common, such as a horse that remains long and woolly in early summer or one that sheds an inordinate amount of hair and becomes nearly bald before its summer coat grows in. This is generally seen when the gradual temperature change from summer to spring is nearly nonexistent and the winter turns to summer abruptly. When the shedding process begins, the horse will enjoy being scratched and will eagerly rub its body on fences or trees to remove the old coat. A horse's summer coat will be fine, resembling soft wool.

    Encourage Shedding

    • If a horse maintains its winter coat through spring and lives in a humid climate, it may contract rain rot or other fungal or bacterial skin diseases, such as ringworm due to high moisture levels. Encouraging the shedding process promotes healthy skin and a beautiful summer coat by minimizing bacterial and fungal infections and increasing circulation. Providing a horse with adequate daily exercise and ample turnout during warm sunlight hours promotes the horse's natural shedding process. Offering a balanced diet in combination with performing daily massage and grooming with a curry comb, dandy brush, shedding blade or grooming mitt especially after exercise will remove dead hair, stimulate the horse's oil glands and more quickly reveal the horse's soft, glossy summer coat.