Thrush and Canker
Thrush is a common bacterial/fungal infection which affects the frog and sole of the foot, producing malodorous, black necrotic material particularly in the grooves between the frog and the sole (frog sulci). If left untreated, it can affect deeper structures within the foot. It is most commonly seen in horses kept in damp conditions or through poor hygiene.
However, it can occur in horses kept in a clean environment, if the frog is overgrown.
Canker is a disease affecting the soles charicterised by a foul smelling creamy exudate. Canker is similar, but a more serious condition than thrush. Although it is rare, unlike thrush it can be difficult to solve. It is a severe bacterial/fungal infection (proliferative pododermatitis) that generally originates in the frog, and affects the heels, horn and underlying structures of the hoof. The clinical signs are the development of a foul-smelling white/grey pus in and around the frog and the presence of granulation-like tissue which often bleeds. Lameness is often variable depending upon the depth of structures involved.