678 DISEASES OF THE SKIN. 



neglected cases, into a low form of fibrous tissue, constituting 

 what is termed elephantiasis ; in some cases the affected limbs 

 become enormously enlarged from this cause. 



The causes of grease are both intrinsic and extrinsic. Of the 

 intrinsic and predisposing, " breed " is the most common, grease 

 being generally met with in hairy-legged cart-horses with big 

 broad feet and light " washy " bodies. Some are of opinion that 

 white legs are peculiarly liable to this disease; but a careful 

 and impartial investigation of the matter has led me to conclude 

 that this idea involves a popular fallacy. 



The exciting causes of grease are, improper food, especially 

 moist, inferior, and cooked food, clipping the hair of the heels 

 and legs, filth, and neglect. 



In some instances the best bred and best cared for horses are 

 liable to grease ; but in them it scarcely ever assumes a chronic 

 character, but partakes more of an erythematous than of an 

 eczematous nature. In race-horses, the process of sweating 

 induces cracked heels ; the sweat, running down the hollow of 

 the heel, dries, and leaves the part impregnated with its salts, 

 which act as irritants to the skin. 



IMPETIGO LABIALIS ET FACIALIS. 



The disease occurs in the lower animals as crusta labialis, 

 from eating some kinds of food, and is chiefly seen affecting 

 animals with white faces and legs. Some veterinarians state 

 that it is unknown to attack any but the white portion of the 

 skin, and that animals without white hairs are exempt from the 

 disease. Professor EoU, of Vienna, refers to it in the following 

 terms : — There occurs amongst horses with white faces, and only 

 at pasture, an eruption which consists in small pustules over 

 which yellow crusts form, and which adhere to the rough and 

 thickened skin. An ointment is required to favour the separa- 

 tion of the scabs, and no further treatment is called for. 



Mr. Gamgee mentions several other authorities, who describe 

 the disease as occurring upon white parts of the body, and that 

 its oiigin is due to the eating of vetches which had becom.e 

 subject to honey-dew ; buckwheat in flower and seed ; and hot 

 and wet weather, after animals had eaten of a variety of Avild 

 polygonum ; and that in some instances the white portions of 



