SA7.Y DISTiASSS. 273 



often connected with a vegetable growth, but this form is dis- 

 tinguished by extreme tenacity, and a gradual progress from its 

 point of origin; that which is dependent on constitutional 

 causes is more diffused. They depend on the general causes 

 of skin diseases :— heating, unsuitable diet, sudden changes, 

 imperfect grooming, heats of summer, disorders of the lungs, 

 bowels, liver, or kidneys, on oxalic acid in the blood, and some 

 constitutional causes. Beside the scurfiness and loss of hair, 

 the itching is often so extreme as to render the subject almost 

 unmanageable, and useless for Avork. 



Trea/incnf. — A moderate laxative diet, consisting in part of 

 roots (carrots and turnips), the free administration of alkalies 

 (carbonate of potassa or soda, etc.), and if still inveterate, a 

 prolonged course of arsenic will be requisite. Locally use 

 mercurial ointment, or, if extensive, sulphur or tar ointment, 

 etc. 



BOILS. FURUNCLFS. 



These are too well known to need description. They con- 

 sist in circumscribed inflammation of the deep layers of the 

 skin, with pustule and sloughing of a limited part of the fibrous 

 tissue. I'hey are not uncommon on the legs of horses, and if 

 a number appear in succession, are a source of great trouble. 



T?'eai//ienf.--Wh\\c sfU a simple inflamed nodule they may 

 often be arrested by incising crucially with a sharp knife and 

 applying cold water bandages. Or apply a poultice or thick 

 wet cloth to bring quickly to a head. If the resulting sore is 

 indolent or unhealthy, touch witli nitrate of silver. The free 

 internal use of alkalies (carbonate of soda) sometimes checks 

 their production. 



NERVOUS IRRITATION OF THE SKIN. NEITROSIS. PRURIGO. 



This is often seen in horses that are overftd on grain 

 (especially the more stimulating varieties) and hay, and that 



