Sheath rot is caused by a bacterium and urea reaction from the urine. The reaction causes irritation of the prepuce. Sheath rot primarily occurs in rams on high-protein rations. Control of sheath rot consists of changing the ration. To reduce the potential for sheath rot, sheep can be grazed on dry grass pastures or fed a grass hay in a drylot. External lesions associated with sheath rot can be treated with one part copper sulfate and eight parts of petroleum jelly, or with antibiotic ointments.