DISEASES OF THE SKIN. 167 



In such instances eczema occurs symptomatically as a consequence of 

 some constitutional disturbance. In other cases, the disease is induced 

 by the direct application of irritants heat, cold, strong ointments of sul- 

 phur, tar, and blisters. 



It may attack several animals at the same stable, and this may lead 

 one to suppose that it is true scabies; but it is not so, and the reason 

 why several animals are thus attacked is explainable by the fact that 

 they are all partaking of the same kind of food, and subjected to the 

 same treatment in other ways. 



Lichen, Rat Tails, 



is confined to the legs of horses, and situated along the course of the 

 flexor tendons. Sometimes all four legs are affected, frequently one or 

 two; and from the peculiarity of appearance it gives to the legs the dis- 

 ease is known as " Eat tails." This appearance is due to an exudation 

 around the hair follicles; the hairs remain unchanged, except from fric- 

 tion, and emerge from an elevated papule, giving to the leg an appear- 

 ance of being covered by the tails of rats. 



Eczema Pustulosum. 



Synonym. — Grease. 



Grrease is a disease resulting from inflammation of the sebaceous 

 glands of the skin in or about the heels. 



The sores resulting from the attack always present a very unhealthy 

 appearance, and give rise to an offensive smelling discharge. If neglected, 

 they will assume an ulcerative character with deep raw and excessively 

 tender cracks; or the disease may in neglected and aggravated cases go 

 on still further, until granulations called " grapes " are formed, accom- 

 panied with much general swelling of the leg. Neglected grease not in- 

 frequently produces more or less permanent thickening of the skin, and 

 afterward a predisposition to a recurrence of the attack. 



Any very sudden change from heat to cold, or from cold to heat, is 

 very likely to derange the function of the skin. Hence washing the 

 legs, especially with hot water and allowing them to dry by evaporation, 

 or neglecting to dry them after strong exercise, readily induce either 

 cracked heels or grease. "When flannel bandages are employed as a 



