FISTULOUS WITHERS 3I 



tococci in large numbers. A few other bacteria, mostl)" micrococci, 

 were associated with them. 



No. 2. An adult female, black, emaciated, but in much better flesh 

 than No. i. The two fore feet and the left hind one were affected. The 

 hind foot and the right fore one were discharging. The left fore foot 

 was badly swollen above the hoof but the swelling did not extend high 

 up the leg. Fluctuation was marked. The skin was shaved, washed, 

 disinfected and the abscess opened. A thick creamy pus was expressed. 

 From this a number of tubes of media were inoculated and in each a 

 streptococcus developed in pure culture. The pus from the discharging 

 feet contained a streptococcus with other bacteria. The feet were 

 treated locally with disinfectants by Dr. Law. In recovering there was 

 considerable thickening of the interdigital tissue. In this case the 

 suppuration had not extended under the nails. 



V. 



§ 16. Fistulous withers and poll-evil. Recent inves- 

 tigations indicate that these very common and troublesome 

 local diseased conditions are either directly or indirectly the 

 result of bacterial invasion. This conclusion is tentatively 

 drawn from the fact that the bacteriological examinations made 

 froin the pus and from recent lesions in the.se affections invari- 

 ably reveal the presence of streptococci or micrococci, or both. 

 Gay found a streptococctis in each of seven cases of common 

 fistulous withers and in two cases of poll-evil. It was invari- 

 ably a.ssociated with a micrococcus. He found in five cases of 

 deep seated shoulder abscesses M. pyogenes aureus only. It is 

 instructive to note, that bacteria clo.sely resembling this organ- 

 ism have frequently been found in the deeper layers of the skin. 

 The mechanical injuries commonly attributed as the primary 

 cause consist usually of little more than skin irritation from ill 

 fitting harnesses, saddles or from blows. While these are 

 mechanically not extensive, they are sufficient to liberate into 

 the juices of the subjacent tissues the bacteria deeply seated in 

 the integument. The inflammatory process leading to sup- 

 puration, the formation of fistulae, the new formation of fibrous 

 tissue in the affected parts, and even the bone necrosis occa- 

 sionally .seen are all possible and rational results of the activi- 

 ties of the pyogenic bacteria found in the lesions. There is 



