GHEASE IMPETIGO ERYS1PELATODES. 141 



virus, and which is commonly the result of diffuse cutaneous 

 inflammation occurring under a variety of circumstances, and 

 often as a sequela in cases of inveterate cracked heels. 



The lymph which bursts from the pustules in grease irri- 

 tates the skin, which becomes sore and partially denuded of 

 hair. The disease is then very apt to assume a chronic 

 character. The heat and pain are no longer so marked, 

 there is a tendency to chronic oedema, and the skin is 

 constantly moist, or feels greasy, owing to a fetid and thick 

 discharge, which dries and mats the hairs together, and pro- 

 duces scabs, which accumulate and form a solid layer on the 

 hairy legs of cart-horses. Ulcers and fissures of various 

 depths occur, the skin undergoes disorganization, and be- 

 comes studded by fungoid masses of granulations, which 

 spring from the unhealthy sores, or by abnormal deposits of 

 cuticle over clusters of hypertrophied papillae. These irregu- 

 lar excrescences have been termed ' grapes.' In some cases 

 the lymphatics of the limb are apt to inflame, abscesses, and 

 even farcy buds form. In other cases the acrid discharge 

 induces degeneration of the frog and sole, so that the malady 

 becomes complicated by an attack of canker. Professor 

 Hering of Stuttgart has found in chronic grease large num- 

 bers of acari similar to those found in scabies. 



The limb affected with chronic grease is apt to become 

 enormously enlarged, and the skin acquires great thickness. 

 The name elephantiasis has been given to this condition, 

 which is well represented in the annexed engraving, on next 

 page, from a photograph made by me of a remarkable speci- 

 men in the Berne Museum. 



The causes of grease are numerous. Low-bred horses, 

 especially those with abundant hair on their limbs, and bred 

 on damp, marshy lands, are very liable to its attacks. Wet 

 and dirt are often exciting causes, and some seasons the 



