74 Principles Of veterinary SUrGERy 



flow freely into the legs, but often there is not sufficient force 

 to again lift it back through its upward, tortuous course to 

 the heart. Under such circumstances oedema is the inevit- 

 able result. 



Pendant parts of the body (the legs, the sheath, the 

 abdominal walls, the pectoral region) are the favorable 

 locations for oedematous swellings. Here the return current 

 of blood is at a disadvantage while the direct current, — the 

 arterial, — is favored by gravity. The blood flows freely into 

 such parts, but as it cannot as easily return, the most trivial 

 interference with the current will favor transudation from the 

 peripheral capillaries, and CEdema is the result. GEdema is 

 also favored in such tissues by the rather loose arrangement 

 of the subcutaneous connective tissue and the spacious cavi- 

 ties it affords the transuded fluid. 



The common oedemas seen in animals, are: (i) oedema of 

 the sheath and prepuce, caused from bruises, filth, idleness, 

 tumors, castration, etc.; (2) oedema of the extremities, 

 caused by bruises, wounds, debility, scratches, febrile dis- 

 eases, etc. ; (3) oedema of the abdomen, caused by contu- 

 sions, wounds, pregnancy, febrile diseases, general debility, 

 erythema, etc. ; (4) ascites of the dog, due to pathologic 

 conditions of the liver, kidneys or tricuspid valves, tumors 

 compressing the vena cava, etc.; (5) hydrocephalus of the 

 horse, due to obstruction of the cephalic veins, lesions of the 

 heart, tumors, etc. 



Besides these special examples oedema is found in con- 

 nection with almost every inflammatory swelling of trauma- 

 tic origin, with every abscess of any considerable dimension, 

 and with every wound that divides veins. In these examples 

 there is no plain line of demarcation between the oedema 

 and the inflammatory swelling. The former surrounds the 

 latter and is especially prominent in the tissues farthest from 



