DISEASES OF THE SKIN. 325 



assumes a persistent tendency, give a tablespoonful of the following 

 powder in the feed three times a day : Cream of tartar, sulphur, and 

 nitrate of potash, equal parts by weight; mix. 



Eczema is a noncontagious inflammation of the skin, characterized 

 by any or all of the results of inflammation at once or in succession, 

 such as erythema, vesicles, or pustules, accompanied by more or less 

 infiltration and itching, terminating in a watery discharge, with the 

 formation of crusts or in scaling off. The disease may run an acute 

 course and then disappear, or it may become chronic; therefore, two 

 varieties are recognized, vesicular, or pustular, and chronic eczema. 



Causes. — Eczema is not so common among cattle as in horses and 

 in dogs, in which it is the most common of all skin diseases. Among 

 cattle it is occasionally observed under systems of bad hygiene, filthi- 

 ness, lousiness, overcrowding, overfeeding, excessively damp or too 

 warm stables. It is found to develop now and then in cattle that are 

 fed upon sour substances, distillery swill, house or garden garbage, 

 etc. Localized eczema may be caused by irritant substances applied 

 to the skin — turpentine, ammonia, the essential oils, mustard, Spanish 

 fly ointment, etc. Occasionally an eruption with vesiculation of the 

 skin has been induced by the excessive use of mercurial preparations 

 for the destruction of lice. It is evident that eczema may arise from 

 local irritation to the skin or from an auto-intoxication. Cattle fed 

 on the refuse from potato-starch factories develops most obstinate and 

 widespread eczema, beginning on the legs. 



Symptoms. — In accordance with the variety of symptoms during the 

 progress of the disease we may divide it into different stages or periods : 



(1) Swelling and increased heat of the skin; the formation of vesicles, 

 which are circumscribed, rounded elevations of the epidermis, varying 

 in size from a pin head to a split pea, containing a clear, watery fluid; 



(2) exudation of a watery, glutinous fluid, formation of crusts, and 

 sometimes suppuration, or the formation of vesicles containing pus 

 (pustules); (3) scaling off (desquamation), with redness, and thicken- 

 ing of the skin. From the very beginning of the disease the animal 

 will commence to rub the affected parts; hence the various stages may 

 not always be easily recognized, as the rubbing will produce more or 

 less abrasion, thus leaving the skin raw — sometimes bleeding. Neither 

 do these symptoms always occur in regular succession, for in some 

 cases the exudation will be most prominent, being very profuse, and 

 serve to spread the disorder over a large surface. In other cases the 

 formation of incrustations, or rawness of the skin, will be the most 

 striking feature. The disease may be limited to certain small areas, 

 or it may be diffused over the greater part of the body; the vesicles, 

 or pustules, may be scattered in small clusters, or a large number run 

 together. The chronic form is really only a prolongation of the disease, 



