432 OPERATIONS ON THE DIGESTIVE APPARATUS. 



made the same experiment, but failed to obtain a successful 

 result. 



3d. Surgical Operations for the Constriction of the Tumor. — 

 Modes of surgical treatment are numerous, usually having in view 

 the destruction of the hernial sac, by the process of mortification, 

 so controlled and directed as to bring about the necessary work 

 of adhesion between the walls of the sac, above the line where the 

 mortification begins, with the formation of a secondary cicatriza- 

 tion between the edges of the skin, where the mortified sac has 

 dropped off. 



Before casting the animal, without which the operation cannot 

 be performed, the surgeon must satisfy himself that the hernia is 

 reducible, and that there is no adhesion, and should carefully 

 measure the dimensions of the sac in order to know accurately 

 where the constriction must be applied. The animal must be 

 placed weU on his back, with his hind quarters elevated — a posi- 

 tion which is sometimes sufficient alone to enable the hernia to 

 reduce itself. If that fails to occm-, the sac can be evacuated by 

 the taxis. It is then to be well stretched, and the application of 

 the means of constriction proceeded with. 



These means are many, but may be considered under the three 

 heads of the ligature, the clamp and the suture — all of which are 

 occasionally combined in use, as the ligature with the suture, or 

 the suture with the clamp. 



(«) The Ligature. — This old mode of operation consists in 

 the appHcation — the hernia having been reduced — of a strong 

 cord, firmly tied at the base of the hernial pouch. 



The modus operandi is very simple. The hernia being already 

 reduced, either by the taxis or by the power of gravitation, as 

 before mentioned, and the horse in the right position, on his back, 

 the sac is raised from the abdomen, and a strong Hgature, firmly 

 tightened, is appHed at its base, a strong fishing line forming the 

 best of ligature for this purpose. The degree of tightness of the 

 ligature must be such that the mortification of the sac will be a 

 gradual process, and that it does not slip from the waUs of the 

 sac, on account of the progress of the inflammatory swelling. 

 Still this constriction must not be permitted to become so ex- 

 treme as to produce too rapid a sloughing of the skin, with the 

 possible result of a calamitous eventration. 



In order to prevent the displacement of the ligature, some 



