Cracked Heel

Cracked heel, greasy heel, scratches (in the US) are all names for mud fever. Perhaps the term seemed apt because mud fever is often observed first in the hollow of the heel, but it soon spreads over an increasing area of the heel, pastern, and ankle - if left unattended.  Initial signs involve inflammation with the hairs standing up unevenly. 
The infected areas later become  hot and crusty with epidermal (skin) cracks and scabs of varying sizes, .  Hair often starts falling out and there may be a watery secretion.  Lameness can be present, and the area is certainly tenderness to the touch.

The treatment of this condition, which is the same as for mud fever, must be prompt.

The skin must be prevented from coming into further contact with the wet or mud, whilst the condition is being treated.

All the scabs must be removed, so that the treatment can reach the skin.

The infection must then be treated with a product that attacks the bacteria.