126 PRIN:CIPLES OF VETERINARY SURGERY 



Patiiogenicity. — From the experiments already men- 

 tioned it is evident that the botryococcus produces a neo- 

 plasm when injected into horses. It is also found in harness 

 and collar lesions that tend to encroach upon the surround- 

 ing tissues. It is found very frequently in the scirrhous cord 

 following castration. It is probably the specific bacterium 

 of this disease in the horse, although it cannot be discovered 

 in the recent case. All of the old scirrhous cord examined 

 at the Chicago Veterinary College during four years were 

 found to contain them. The pathogenic role of the botryo- 

 coccus in this affection, is evidently that of perpetuating 

 rather than causing the morbid process. The pre-existing 

 funiculitis caused by improper methods of castration is 

 primary and gives the botryococcus an avenue of entrance 

 and a suitable environment for growth. Besides provoking 

 the production of new tissue, it is pyogenic (See chapter on 

 Botryomycosis, Part II). 



B. SPECIFIC SURGICAL MICRO-ORGANISMS. 



In studying the surgical bacteria, it must be remembered 

 that the so-called pyogenic forms are not numerous, but 

 that many other micro-organisms may cause pus formation. 

 Pyogenesis is not a specific disease. It is simply the result 

 of the reaction of the organism against the micro-organism, 

 and may therefore occur in the presence of most any patho- 

 genic bacterium that attempts, but fails, to successfully in- 

 vade the living body. The first seven forms described above 

 might be appropriately referred to as the microbian agents 

 most likely to provoke suppuration in animals. They 

 might also be appropriately accused of being rather unsuc- 

 cessful invaders. At most every attempt they make to enter 

 the organism they are successfully repulsed by the leuco- 

 cytes, and suppuration is the result. Occasionally, however, 

 their attack is successful. They surmount the barrier put up 



