240 THB horsb;. 



If caustics are inserted, they cause sloughing of healthy tissues and favor 

 the formation of sinuses by producing sloughs below the point of incis- 

 ion. If the abscess has existed for some time and has not opened, its 

 walls become thickened, the pus granular or inspissated, then, after an 

 opening has been made by the knife and the contents washed and 

 squeezed out as much as possible, the plan of treatment is materially 

 different. There is enormous thickening of the walls, which must be 

 destroyed and sloughed out by caustics. The best plan here is to make 

 the first incision in the highest point of the swelling, introduce a piece 

 of caustic potash (fused) one to two inches in length, carefully plug the 

 opening with oakum or cotton, and secure the horse so that he can not 

 disturb the parts by rubbing or biting them. The skin of the shoulder 

 and entire leg must be thoroughly greased with lard or oil in order to 

 prevent the caustic (should it escape) from excoriating the skin over 

 which it flows. Twenty-four hours after the introduction of the caustic 

 the plug is to be removed and hot fomentations applied. As soon as the 

 discharge is again established we must make another opening with the 

 knife or seton needle as low as possible, and keep this opea with a seton. 

 The object of making the first incision on top is to insure the retention 

 of the caustic until it has attacked the entire inner surface of the cavity. 

 If this is done the caustic causes sloughing of everj^ portion of the dis- 

 eased parts, leaving a healthy granulating surface underneath, which 

 only requires that the depending orifice be kept open and the cavity 

 washed out with a weak antiseptic solution once or twice a week to 

 effect a cure. 



In many cases of fistula there is more than one sinus or pipe that must 

 be explored, laid open with the knife if possible, or opened through its 

 bottom by means of a sharp seton needle, passing a tape through the 

 openings, and retaining it in this position for some time. If the pipes 

 are directed straight downward between the shoulder blade and the spine 

 it is difficult or impossible to make a counter opening, and the case be- 

 comes serious or intractable. Caustic solutions must now be injected 

 carefully into the sinuses with the hope of reaching every diseased part. 

 Probably the best is granular chloride of zinc, one ounce to a half pint 

 of water. This should be injected three times during one week, after 

 which a weak solution of the same, or the sulphate of zinc, is to 

 be occasionally injected. Pressure must be applied from below, and en- 

 deavors made in this manner to heal the different pipes from the bottom. 

 Should the bones of the withers or the shoulder blade be diseased the 



