Pityriasis and psoriasis are the two affections which come properly in this class.

Pityriasis, as the name implies, is a disease of the skin in which the surface becomes covered with white scales having the appearance of bran. It is usually associated with poverty, and disappears as the general condition improves. Horses suffer from the disease occasionally, but not so frequently as cattle.

Treatment

According to Williams, the disease in the horse is associated with presence of oxalates in the urine, and he accordingly advises that carrots and turnips and all kinds of food which furnish sugar should be withheld. We would, however, suggest a liberal allowance of green food when such can be obtained, and a generous but well-regulated corn ration. The chief object to be obtained is to improve the nutritive function of the skin. For this purpose a powder consisting of equal parts of sulphur, resin, and nitrate of potash should be given twice daily, and a dose of solution of arsenic with the mid-day feed. The patient should not be allowed to lead a sedentary life, but be freely exercised every day.