The scientific name is Dermatophilosis. A Dermatophilus bacteria is involved. It causes skin lesions in horses and cattle as well as lumpy wool in sheep. Strawberry foot rot is also the result of usually wet conditions and the same bacteria.
Animals need to be placed in a dry environment and topical products such as D-Thrush are helpful. If these conditions are met then one subq injection of Zactran, 2cc to market weight lambs, 4cc to ewes and 5cc to rams and repeated in 23 days if necessary should remedy the problem.