INFECTIOUS MASTITIS IN GENERAL 29 



septic intoxication, or develop into exudative gangrene 

 and then septic-putrid intoxication with the same symptoms 

 as before described, and these conditions may terminate 

 in death. 



Termination. — Stroma-infection or interstitial mas- 

 titis very seldom terminates in death. Healing is the rule. 

 The wounds heal after sloughing of the necrotic parts, with 

 more or less sclerosis and parenchymatous atrophy. 



Nodular necrosis following milk-infection or the less 

 frequent embolic necrosis may form chronic wounds which 

 may induce a sort of relative healing through encapsulation. 



Stroma-infection of Chronic Character [Chronic 

 Interstitial Mastitis^. — The action of the bacteria is of 

 a chronic progressive character. 



Ports of Infection. — These infections may take place 

 through the teat canal, through wounds or through the 

 blood stream. 



In the latter case the infection is always primary in the 

 stroma due to its position in the udder. Whatever the 

 port of entrance may be the organisms are taken up by 

 the leucocytes and carried into the lymph spaces of the 

 stroma. Here the leucocytes soon become paralyzed and 

 are necrotized by the bacteria. 



Local Conditions. — The primary lesion consists of 

 many single spreading areas of necrosis in the stroma 

 around the point of infection in the teat canal, wound or 

 at the point of infection from the blood stream. 



Around each primary lesion the inflammation produces 

 a strong ring of leucocytes and outside of this a wall of 

 new- formed connective tissue. 



Thus the inflammation produces many small areas or 

 nodules the size of a pin's head or smaller (Fig. 5). 



The progressive character, that is, the chronic enlarge- 

 ment of the primary lesion, the necrosis, is diagnostic of 

 this infection. The primary lesion is chronic, as it were. 



