SYMPTOMS AND PROGRESS OF SHOULDER ABSCESS. 



485 



by continuous pressure of badly-fitting collars, as indicated by their 

 occurring mainly in draught horses, usually in those drawing heavy 

 loads. Viborg viewed them as complications of strangles. Every 

 practitioner must have seen many draught horses with this shoulder 

 abscess, but riding horses seldom seem to be so affected. Stock- 

 fleth, however, reports a case in a horse which had been confined 

 for several months to the stable on account of lameness ; but this 

 may be regarded as the exception which proves the rule. It is 

 specially noteworthy that, even from their earliest beginning, these 



Fig. 385. — Multiple abscess formation in the shoulder-region due to Botryomyces. 



abscesses contain pus, in which botryomyces and pus cocci are almost 

 invariably present. This fact has been amply proved by the large 

 number of these abscesses containing botryomyces opened in the 

 Berlin and other cliniques during the last few years. 



But how does the infection occur ? Though it is clear that 

 infection with cocci must be associated with injury caused by the 

 collar, it is by no means clear how the cocci penetrate to the deep- 

 lying seat of abscess through uninjured skin. Cadiot regards this 

 objection as valueless ; the skin may and generally does appear 

 intact, yet very slight excoriation permits cocci to penetrate, and by 

 the time the abscess appears, the inoculation lesion will be healed 

 or not discoverable. Frohner and others considered that the 

 botryomyces gains entrance through cutaneous wounds or abrasions 



