292 PRINCIPLES OF VETERINARY SURGERY 



vascular, connective tissue has been replaced' by a tissue of 

 sclerosis." (Letulle) 



PROGNOSIS. — The seriousness of a wound depends 

 upon different factors. When the Avounded tissue is a healthy 

 one and that of a sovtnd animal, the cicatrization is generally 

 rapid and the termination is simple. Matters are, however, 

 different when the injured animal is diseased or placed in 

 bad hygienic conditions, or when the injured tissues were 

 previously impaired. The prognosis is then dependent on a 

 number of factors, viz. : the animal wounded, the wound, 

 the environment and the part wounded. 



The environment in which a wounded patient is placed 

 is significant so far as the progress of the disease is con- 

 cerned. Formerly, when rules of hygiene were little known, 

 animals kept in infected places frequently died. Complica- 

 tions were the inevitable result. The animals wounded or 

 operated upon in the presence of spectators in the hospitals 

 of Alfort, from the time of Renault^ almost invariably suc- 

 cumbed to purulent infection. With improvement in the 

 surroundings this sequel disappeared. These complications 

 were then attributed to changes in the surrounding atmos- 

 phere, but as the researches of chemists did not furnish the 

 necessary explanation, search elsewhere became necessary. 

 In i860 the great controversy about spontaneous generation 

 occurred. After impassionate conflicts the victory remained 

 with Pasteur, who cleared up points that had heretofore 

 remained obscure. It is easy to understand the successes 

 achieved by Lister and J. Guerin who, placing the wounds 

 out of the reach of air, thus preserved them from any infec- 

 tion from without. It is, however, established today that, 

 since the beginning, too much importance has been attached 

 to dust and aerial germs. Nearly always the complications 

 are traceable to the operator or his instruments. It is by 

 their agency that micro-organisms are carried to the wounds. 



