WOUNDS AND THEIR TREATMENT. 505 



application of caustics which will cause a sloughing of all of the 

 unhealthy tissue, and will also stimulate a rapid increase of healthv 

 organized material to replace that destroyed in the course of the 

 development and treatment of the disease. Threads or cords soaked 

 in gum-arabic solution and rolled in powdered corrosive sublimate 

 may be introduced into the canal and allowed to remain. The skin 

 on all parts of the shoulder and leg beneath the fistula should be 

 carefully greased with lard or oil, as this will prevent the discharge 

 that comes from the opening after the caustic is introduced from 

 irritating or blistering the skin over which it flows. In obstinate 

 cases a piece of caustic potash (fused) 1 to 2 inches in length may 

 be introduced into the opening and should be covered with oakum or 

 cotton. The horse should then be secured so that he can not reach 

 the part with his teeth. After the caustic plug has been in place for ; 

 24 hours, it may be removed and hot fomentations applied. As soon 

 as the discharge has become again established the abscess should be 

 opened from its lowest extremity, and- the passage thus formed may 

 be kept open by the introduction of a seton. If the pipes become 

 established in the deep tissues beneath the shoulder blade or among 

 the spines of the vertebral column, it will often be found impossible 

 to provide proper drainage for the abscess from below, and treat- 

 ment must consist of caustic solutions carefully injected into all parts 

 of the suppurating sinuses. A very effective remedy for this pur-, 

 pose consists of 1 ounce of chlorid of zinc in half a pint of water,; 

 injected three times during a week, after which a .weak solution of 

 the same may be occasionally. injected. Injections of Villate's solu- ; 

 tion or alcoholic solution of corrosive sublimate, strong carbolic acid, 

 or possibly oil of turpentine will also prove beneficial. Pressure 

 should be applied from below, and endeavors made to heal the vari- 

 ous pipes from the bottom. 



Should the swelling become general, without forming a well-defined 

 tumor, the placing of 20 to 30 grains of arsenious acid, wrapped in a 

 single layer of tissue paper, in a shallow incision beneath the skin, will 

 often produce a sloughing of the affected parts in a week or 10 days, 

 after which the formation of healthy tissue follows. The surround- 

 ing parts of the skin should be protected from any damage from 

 escaping caustics by the application of lard or oil, as previously 

 suggested. 



Although the successful treatment of fistulas requires time and 

 patience, the majority of cases are curable. The sinuses must be 

 opened at their lowest extremity and kept open. Caustic applications 

 must be thoroughly used once or twice, after which mild astringent 

 antiseptic washes should be persistently used until a cure is reached. 



It sometimes happens that the erosions have burrowed so deeply or 

 in such a direction that the opening of a drainage passage becomes 



