PITYRIASIS : SQUAMOUS SKIN DISEASE : HORSE. 



Dry, scaly, or powdery affection. Causes : Fine, thin, dry skin with 

 little hair, race, Arab, Barb, racer, trotter, nervous temperament, age, dry 

 summer heat, dry winter cold, foul skin, caustic soaps, ingestion of salt, 

 iodides, bromides, etc., derangement of internal organs bacteria or 

 cryptogams. Symptoms : scurfy patches, general or circumscribed, where 

 little hair is, where harness rubs, depilation of ears, crest, tail, shoulder, 

 back. Diagnosis, from eczema by lack of pruritus, of rapid extension, of 

 thickening of the skin, from acariasis by absence of acarus. Treatment : 

 correct disorder of stomach, liver, or kidneys : green, succulent or nutritive 

 food ; alkalies ; arsenic ; tonics ; locally potash soaps, ointments of tar. 

 birch oil, creolin, creosote, naphthalin, lysol, mercury, iodine, salicylic acid, 

 zinc oxide. 



This is a skin disease characterized by excessive production of 

 epidermic scales, and depilation without any attendant elevation 

 of the skin. The desquamation may be .of fine scales like wheat 

 bran, or of a fine dust like flour. 



Causes. The disease is especiallv characteristic of animals in 

 •which the skin is naturally fine, thin and dry and covered sparsely 

 -with hair. It is therefore more common in the Arabian, Barb, 

 English racer, American trotter and other breeds of a nervous 

 organization than in the heavier draught breeds. Old horses in 

 which the skin is drier and the hair thiniler are more subject to it 

 than the young. Again it has been especially noticed in the 

 heats of summer with thin coat and a withering action of radiant 

 lieat on the skin, and less frequently in winter when the blood is 

 driven from the surface by cold. Much also depends at times on 

 the lack of grooming, on the accumulation of dust and dried up 

 secretions about the roots of the hair, and on washing with 

 caustic irritant soaps especially in long-haired regions. It has 

 even been claimed that the ingestion of salt, potassium iodide, or 

 bromide, etc., contributes to the affection. There is undoubtedly 

 a certain individual predisposition to the disease, shown as already 

 stated in certain breeds, but also inherent in particular families 

 and even animals, and associated not only with the character 

 of the skin, but also probably with variations in the activities and 

 products of various internal organs. In man pityriasis versicolor 

 511 



