Hoof abscesses are probably the most common cause of acute severe lameness in horses encountered by veterinarians and farriers. A hoof abscess can be defined as a localized accumulation of purulent exudate located between the germinal and keratinized layers of the epithelium, most commonly subsolar (beneath the sole) or submural (beneath the hoof wall).

Organisms that are responsible for a hoof abscess gain entry through the hoof capsule (epidermis) into the inner subsolar/submural tissue (dermis) where the organisms propagate and initiate the formation of an abscess. Foreign matter (such as gravel, dirt, sand and manure coupled with infectious agents such as bacteria or fungal elements) generally gain entry into the hoof capsule through a break or fissure in the sole-wall junction somewhere on the solar surface of the foot.

Anatomical Review Of Abscesses

A brief anatomical review of hoof capsule structures may be helpful before discussing hoof abscesses. The foot is composed of the hoof, the skin between the bulbs of the heels and all the structures within. The structures of the hoof complex comprise the hoof capsule, distal phalanx, digital cushion, ungual cartilages and deep digital flexor tendon.¹ These biological structures are susceptible to trauma and are prone to various disease processes including infections (hoof abscesses, puncture wounds) and keratomas.