82 MASTITIS OF THE COW 



secondaiy infection with actinomycosis is possible but 

 occurs infrequently. 



Saprophytic invasion is common and appears to favor 

 the infection. It causes milk- or (and) wound-gangrene. 



Milk-gangrene is very common. The croupous exudate 

 in extensive pyobacillosis with secondary milk-infection 

 predisposes toward this complication. This exudate as 

 before mentioned can remain located in the teat canal and 

 constitute a good bridgework. Secondary milk-infection 

 also favors the beginning of this complication to a great 

 extent. 



Wound-gangrene may develop in a primary or second- 

 ary wound. It is very common and we may say it is the 

 rule if wounds are not treated. 



General Conditions. — Blood-infection. — A necrotic 

 focus may contain a vein which becomes open by perfora- 

 tive ulceration and admits the bacteria which caused the 

 necrosis. These organisms are carried by the venous sys- 

 tem to the lungs. From the lungs the bacteria may enter 

 the pulmonary veins in a similar manner and be carried 

 by the arterial blood stream to one or several other organs 

 of the body, inducing secondary metastatic foci. 



Intoxication. — Pyobacillosis causes a low-gi'ade 

 chronic intoxication, which, like the lesion, has a progressive 

 character. It continues to a chronic progressive emaciation 

 and anaemia with thickening and finally a leatheiy skin 

 and roughened hair coat and finally to fever and death of 

 the animal. 



Complications with acute secondary infections and 

 [or] with gangrene often produce high and continuous 

 fever and may terminate more or less quickly in death of the 

 animal. 



Termination. — The primary condition seldom causes 

 death. It advances by a chronic protracted course, extend- 

 ing over months and years to progressive destruction of 



