502 DISEASES OF THE HORSE. 



escape. After this, and whether we have found matter or not, we 

 must induce an active inflammation of the tumor, in order to pro- 

 mote solution of the thick walls of the abscess. This may be done by- 

 inserting well into the incision a piece of oakum or cotton saturated 

 with turpentine, carbolic acid, tincture of iodin, etc., or we may pack 

 the incision with powdered sulphate of zinc and keep the orifice 

 plugged for 24 hours. These agents set up a destructive inflamma- 

 tion of the walls. Suppuration follows, and this should now be en- 

 couraged by hot fomentations and poultices. The orifice must be 

 kept open, and should it be disposed to heal we must again introduce 

 some of the agents above described. A favored treatment with many, 

 and it is probably the best, is to plunge a red-hot iron to the bottom 

 of the incision and thoroughly sear all parts of the walls of the ab- 

 scess. This is to be repeated after the first slough has taken place if 

 the walls remain thickened and indurated. 



It is useless to waste time with fomentations, poultices^ or blisters 

 in the treatment of cold abscesses, since though apparently removed 

 by such methods, they almost invariably return when the horse is 

 put to work. Extirpation by the knife is not practicable, as the 

 walls of the tumor are not sufficiently defined. If treated as above 

 directed, and properly fitted with a good collar after healing, there 

 will not remain any track or trace of the large, unsightly mass. . 



FISTULAS. 



Definition. — The word fistula is applied to any ulcerous lesion 

 upon the external surface of the body which is connected by ducts, 

 or passages, with some internal cavity. Because of this particular 

 formation the term fistulous tract is often used synonymously with 

 the word fistula. Fistulas may exist in any part of the body, but the 

 name has come to be commonly accepted as applicable only to such 

 lesions when found upon the withers. Poll evil is a fistula upon the 

 poll, and in no sense differs from fistulous withers except in location. 

 The description of fistula will apply, then, in the main, to poll evi] 

 equally well. Quittor presents the characteristic tubular passages of 

 a fistula and may, therefore, be considered and treated as fistula of 

 the foot. Fistulous passages may also be developed upon the sides 

 of the face, through which saliva is discharged instead of flowing 

 into the mouth, and are called salivary fistulas. A dental fistula may 

 arise from the necrosis of the root of a tooth. Again, a fistula is 

 sometimes noted at the umbilicus associated with hernia, and recto- 

 vaginal fistulas have been developed in mares, following difficult 

 parturition. Fistulas may arise from wounds of glandular organs 

 or their ducts, and thus we have the so-called mammary or lacrimal 

 fistulas. 



