This is a contagious disease, due to a minute insect, and presenting symptoms not unlike the last.

Active treatment is necessary for the destruction of the parasite. Paraffin oil, applied once a day, and allowed to dry on the skin, is very efficacious, as is also a mixture of sulphur and common oil, well rubbed into the skin; or oil of tar and sulphur, of each two ounces to a pint of common oil. McDougall's sheep-dip, also Jeyes' fluid, may be used advantageously. The skin should be washed with soap and water before the dressing is applied, and it should be washed again in a day or two after the dressing. Clothing and harness should be thoroughly cleansed, and care should be taken to keep the affected horse from healthy ones.