Thrush is an anaerobic bacteria that is not contagious.
The best control for thrush is proper sanitation. Be sure that the horse’s hooves are cleaned daily and that the stall is cleaned daily with removal of wet spots and manure. If the horse is kept in a run-in shed, the area should be cleaned weekly to help minimize the buildup of organic matter. Copper Tox and Thrushbuster work well for treating thrush. Iodine-based products, such as Povidone, are also very effective.