76 PRINCIPLES OF VETERINARY SURGERY 



remedial expedients, the value of which depends upon the 

 location and the cause. 



The removal of the cause would promptly terminate 

 most any ordinary oedema of animals, but this can seldom 

 eVer-be immediately effected. The divided vein, the ligated 

 vein, the obturated vein, the inflammatory swelling, the de- 

 fective heart, the depressed circulation, etc., which cause 

 oedema can not be dispatched at one stroke. The treatment 

 must, however, be directed at the cause as well as at the ef- 

 fect whenever possible. 



Tonics, healthful exercise, better hygiene, good food and 

 regular dieting must not be omitted in the treatment of 

 oedema's due to, or augmented by, general depression of the 

 circulatory apparatus. 



Ascites of the dog, being due to incurable affections of 

 the liver or other organs, can never be permanently rem- 

 edied. The aspiration of the fluid is always followed by re- 

 filling of the cavity, and the medicines given for the sclero- 

 tic liver are generally ineffectual. 



THROMBOSIS AND EMBOLISM. 



DEFINITION.— Thrombosis is the coagulation of blood 

 within the blood vessels of the living body. It is death of a 

 portion of the blood. The coagulated mass is called a throm- 

 bus. The coagulation of blood after death even if outside 

 of the blood vessels is called a coagulum or a clot. The word 

 "thrombus" is still more properly defined as a fixed coagulum 

 within the blood vessels of a living body. Embolism is the 

 obturation of blood vessels from the lodgment of a solid ob- 

 ject that has floated in the blood current from other parts of 

 the body. The floating particle is known as an embolus. 

 The thrombus is always composed of clotted blood while the 

 embolus may be any floating solid substance, such as de- 

 tached particles of thrombi, clusters of bacteria; clusters of 



