PRINCIPLES OF VETERINARY SURGERY 413 



country practitioners. It is much more rare, for example in 

 the goat, the hog and the dog. 



ETIOLOGY. — Strangles and glanders are frequently 

 complicated by general suppuration. Besides these two spe- 

 cial pathological states, the evolution of purulent infection is 

 subordinate to the environment and the condition of the in- 

 dividual. 



The Environment. — Before Pasteur discovered the lower 

 forms of life it was difficult to explain why all subjects ope- 

 rated upon, both large and small, would die from purulent 

 infection if placed in the certain habitats. The observations 

 of Renault at Alfort showed that matters were the same in 

 veterinary as in human pathology. The renovation of the 

 Alfort hospital and the observance of the rules of hygiene 

 was followed by the complete disappearance of purulent 

 infection. 



The Individual. — If the environment plays an important 

 role in the evolution of the disease, the role of the individual 

 is equally evident. Although infected with agents of sup- 

 puration of considerable virulence all animals are not nec- 

 essarily condemned to die of purulent infection. Some are 

 easy prey for microbian infection. The debilitated, the 

 overworked and the aucemic belong to that category. And 

 besides, the young — the new-born — in which infection 

 through the umbilicus causes a fatal pyaemia, must be taken 

 into account. 



Except in the predisposed, purulent infection will not 

 evolve as the result of any wound whatever. Certain acci- 

 dents are more prone to cause the disease than others. An- 

 fractuous wounds and fistulse from crushing may cause pvfe- 

 mia, while plain wounds, although extensive, are generally 

 without danger. 



In the horse fistula of the withers, poll-evil, quitter, ar- 

 thritis, wounds of castrations, acute mastitis, and purulent 



