473 



where there is left no possibility of its burrowing between the muscles, 

 forming pockets or sinuses, the parts rapidly and permanently heal 

 without any mediation whatever, as though we had been dealing Avith 

 a simple abscess of the withers, and not a true fistula at all. 



Attention is again called to the directions given above as to the 

 necessit}'^ of probing the cavity when opened. If upon a careful exam- 

 ination with the probe we find that there are no pockets, no sinuses, 

 but a simple, regular abscess wall, the indication for treatment is to 

 make an opening from below so that the matter must all escape. 

 Rarel}' is anything more needed than to keep the orifice open and to 

 bathe or inject the parts with some simple antiseptic wash that is not 

 irritant or caustic. A low opening and cleanliness constitute the 

 essential and rational treatment. If caustics are inserted, tlie}^ cause 

 sloughing of healthy tissues and favor the formation of sinuses by 

 producing ' sloughs below the point of incision. 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 

 bj" the knife and the contents washed and squeezed out as thoroughl}^ 

 as possible, the plan of treatment is materially different. There is 

 enormous thickening of the walls, which must be destroj^ed 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) 1 to 2 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 escai)e) 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 dis- 

 charge is again established we must make another opening with the 

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

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

 the retention of the caustic until it has a'ttacked the entire inner sur- 

 face of the cavity. If this is done the caustic causes sloughing of every 

 portion of the diseased parts, leaving a health}' 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 manj^ 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 oijening, and the case become serious or intract- 

 able. Caustic solutions must now be injected carefull}' into the sinuses 

 with the hope of reaching every diseased part. Probably the best is 



