INFECTIOUS MASTITIS IN GENERAL 27 



in the udder may be primary in the stroma, although not 

 coming from the milk into the stroma. The wound is 

 caused by an external violence and is therefore an external 

 wound which opens through the skin. The pathogenic 

 organisms come into the wound from the exterior. The 

 infection through the blood, due to its position in the udder, 

 is always primary in the stroma. 



Furthermore, this infection can be secondary in the 

 stroma when it comes into the stroma from the milk. The 

 wound, or the wounds, are caused by milk -infection with 

 development of necrosis after the occurrence of desquama- 

 tion or secondary wounds. These internal wounds are in- 

 fected by the same infectious organisms which cause the 

 milk-infection [parenchymatous mastitis]. 



The location of the bacteria in these stroma-infections 

 is in the wound secretions and in the primary lesion. 



Local Condition. — The primary lesion extends over 

 the surface of the wound and forms a superficial or more 

 or less deep necrosis. The wound secretion is usually 

 altered by the primary lesion. Following the necrosis of 

 the vessels the lymph or plasma extravasation increases, 

 the blood corpuscles remain for the most part in the vessels. 

 The secretion is colored red by haemoglobin due to necrosis 

 of red corpuscles. 



In stroma-inf ection, through the blood, more frequently 

 larger or smaller embolic areas of necrosis are found. 



The inflammation induces a severe leucocytic emigra- 

 tion into the connective tissue of the walls of the wound 

 and into the wound. The wound secretion is suppurative. 

 It contains a great quantity of cells, leucocytes and young 

 connective cells, has a gray or yellowish-gray color and is 

 somewhat thick. 



Around the necrotic parts a dissecting cell-ring of leu- 

 cocytes forms, which loosens the necrosis. 



The loosened necrotic material can slough directly to 



