272 PRINCIPLES OF VETERINARY SURGERY 



prevented, but its outward flow during the surgical treat- 

 ment of a wound may, in fact, be beneficial in washing out 

 infectious matter. (See Hsemostasis, page 192). 



3. The Sterilization. — The surgical wound made in a 

 clean field requires no form of sterilization because it is not 

 permitted to become infected. All surgical wounds made in 

 an aseptic field are aseptic, and all accidental wounds, no 

 matter how they are made or where they are located, must be 

 regarded as septic and must as a consequence be submitted 

 to the process of sterilization. As far as possible the acci- 

 dental wound is mechanically disinfected, that is the infected 

 tissues are cut away. The newly inflicted wound is thus 

 disinfected by dissecting its mutilated shreds, and the older 

 one is scraped of its infected granulation by curettage or 

 other mechanical means. 



The principles of chemical disinfection consist of render- 

 ing the micro-organisms as innocuous as possible by pro- 

 longed irrigation with weak antiseptics that will not injure 

 the tissues, and then create a condition unfavorable for their 

 growth by depriving them of their natrition. Powerful an- 

 tiseptics, while destructive to the micro-organisms, in one 

 sense, may actually prove harmful by weakening the re- 

 active powers of the living tissues. A half-killed cell falls 

 an easy prey to the wound-bacterium, while on the other 

 hand a bacterium partially blunted with a weak antiseptic 

 is readily englobed by the active leucocytes. It is on this 

 principle that wound disinfection must proceed, whenever 

 prompt cicatrization is essential. On the other hand when 

 the infectious matter threatens life, as in the case of tetanus 

 or rabies, the strongest kind of germicides are demanded. 

 Here the caustic is indicated. 



After the wound is mechanically disinfected, and then 

 chemically disinfected with the weak antiseptic, the next 

 step is to rob the remaining bacteria of food necessary for 



