Prevention is always better than cure, the importance of regular thorough inspection of the horses legs and heels is vital to detect any scabs at the earliest phase.
> Wash the infected area with an antibacterial wash.
> Work it in to a lather and leave for a few minutes. 
> Rinse off with tepid water removing any tufty hair and scabs. 
> Dry the area thoroughly with a clean soft towel, do not over rub as this may damage the skin.
> Liberally apply sulphur powder, this will dry the area and act as an antiseptic. 
> In severe cases the veterinarian may suggest an antibiotic course. 
There are many antibacterial creams and ointments available however the most important treatment is the cleaning and more importantly the drying of the legs.