As many horse owners know, mid-winter brings snow and other forms of precipitation that often continue through the spring—and that can mean wet and muddy conditions for our equine companions.

For horses living outside, these conditions can lead to mud clods and ice balls in the hooves. Prolonged wet conditions can cause very soft feet that are susceptible to more serious problems, including hoof wall separation, thrush, and sole abscesses.


This anaerobic bacterial infection slowly invades the hoof tissue. Thrush is characterized by black, malodorous necrotic, or dead, material in the central or collateral sulci of the frog—the grooves adjacent to and in the middle of the triangle-shaped frog.

Early stages of thrush involve only superficial tissues and do not cause lameness. But if thrush is not treated promptly and properly, the infection can advance into sensitive tissues and internal structures of the foot, such as the digital cushion, hoof wall, and heel bulb; this can lead to lameness.

The main factors causing thrush are excessive hoof contact with moisture and lack of regular foot care, either of which can occur when snow, rain, and cold temperatures cause some owners to be less diligent about mucking the stall, picking out hooves, or turning out horses for exercise.

Although less common, poor hoof conformation can predispose horses to thrush, even when they live in clean, dry conditions.

In most cases, thrush is preventable by maintaining dry footing, clean hooves, and regular turnout or exercise. If you detect signs of thrush