Equine nonproliferative pododermatitis of the frog (thrush): A review

Thrush is the term commonly used to describe nonproliferative pododermatitis of the frog epidermis caused by a bacterial infection. Thrush is commonly encountered in veterinary and farrier practices yet information on the pathogenesis, treatment and prevention of the disease in the equine veterinary literature is lacking. There is a plethora of proposed products and treatments on the market for thrush, yet most lack clinical evidence of efficacy. Clinical signs of thrush can range from black exudate in the sulci of the frog accompanied by a foul odour to bacterial invasion of the frog corium and digital cushion resulting in lameness. Thrush is primarily encountered in a conformationally compromised hoof capsule that is generally associated with an unhealthy frog. As thrush is rarely encountered in a healthy frog, it is important to focus on the farrier practices that may play a role in both the pathogenesis of thrush and its prevention. For successful treatment and prevention of thrush, good basic farrier principles must be incorporated into the treatment protocol.