60 FISTULA AND POLL-EVIL 



swellings that are not easy to differentiate from 

 the saccular and phlegmonous conditions as- 

 sociated with the graver state preceding the 

 fistulous stage. Subcutaneous and subfascial 

 sanguinous sacs and hemotomata complicated 

 or uncomplicated with infection, are the mos^ 

 misleading of these lesions for which fistulas 

 might be mistaken. The differentiation can 

 never be made with certainty until the behavior 

 of the swelling is noted, both before and after 

 evacuating the contents. In fistula such swell- 

 ings accentuate; in the others they subside, 

 either with or without lancing. Besides they 

 are always diffuse whereas the fistulas presents 

 a spherical swelling in almost every instance. 



Although acute diseases running short 

 courses, malignant edema and other erysip- 

 elatous inflammations when attacking the 

 withers may at first mislead the diagnostician, 

 these are recognized by their acuteness and 

 rapid advancement into adjacent regions and 

 the serious concomitant toxemia. 



The early symptoms of the atypical form are 

 likewise very often misleading. That any given 

 harness sore will or will not end favorably is 

 not always easy to determine. Wliat might at 

 first seem like a simple enough harness sore 

 may finally prove to be the initial phase of a 

 bad fistula. On the other liand, a badly in- 



