82 PEINOIPLES OP VETEEINABY SUEGEB7 



Which form of gangrene is more frequently seen in animals f 

 Dry gangrene, as from harness pressure and decubitus 

 (bed-sores). 



Which part of the body is quite often attached by moist 

 gangrene ? 

 The flexion surface of the lower pasterns in gangrenous 

 dermatitis (aggravated scratches). 



How is the gangrenous process usually limited ? 



At the junction of the healthy and necrosed tissues a ■wall 

 of granulations is thrown out by the healthy tissues, by 

 means of which the slough or necrosed tissues are separated 

 from the living parts. This line of granulations, establishing 

 the separation of the dead from the living tissues, is termed 

 the line of demarcation. 



Causes of Gangrene. 



Name the causes of gangrene. 



(1) Mechanical, (2) thermic, (3) chemical, (4) infectious, 

 (5) a combination of the above. 



Describe the mechanical causes of gangrene. 



Most frequent one, consisting of mechanical interference 

 with the circulation of the part, such as contusions, con- 

 tinuous pressure, incarceration, thrombosis, embolism. 



How soon after interruption of the circulation do skin and 

 muscles undergo gangrene f 

 In ten to twelve hours. 

 How soon after interruption of the circulation do the inteS' 

 tines, brain or kidney undergo necrosis ? 



In one to two hours. 



