PRINCIPLES OF VETERINARY SURGERY 71 



is to say, surgical intervention is intended for systemic and 

 not local amelioration. In certain cases free incision and 

 even ablation of the part may be necessary to prevent the 

 burrowing of purulent products into the neighboring struc- 

 tures. Prompt operation upon the fistula of the withers, the 

 poll evil, the quittor, etc., may prevent the formation of com- 

 plicated fistulous tracts, but even here, and always in the 

 superficial gangrenes, the "waiting" treatment is by far the 

 most appropriate. 



Amputati&n, which constitutes the essential treatment 

 for extensive spreading gangrenous conditions in the human 

 being is not applicable to veterinary subjects, except, pos- 

 sibly here and there, in the dog or cat, and occasionally for 

 gangrene of the tails of any of the domestic animals. 



The palpable duty of the veterinarian in the treatment 

 of gangrene is: (i) to apply hot fomentations to encourage 

 the collateral circulation; (2) to incise or ablate when 

 purulent products may penetrate into important neighboring 

 structures; (3) to remove the sloughs or sequestra when 

 they are well separated; and (4) to encourage cicatrization 

 in the usual manner. 



(EDEMA. 



DEFINITION — CEdema is simply the transudation 

 of serum from the blood channels, due to obstruction or 

 retardation of the flow of venous blood toward the heart. 

 When the fluid accumulates in the subcutaneous tissue over 

 a circumscribed area, it is usually referred to as "cedematous 

 swelling" or "simple oedema." If the accumulation is in a 

 cavity it is called "dropsy." In the peritoneal cavity the 

 ng,me "ascites" is given, in the cerebral ventricles, "hydro- 

 cephalus," and in the scrotum, "hydrocele." If spread 

 throughout the subcutaneous and intermuscular areolar 

 tissues it is called "anasarca." 



