100 MASTITIS OF THE COW 



Milk-gangrene does not appear to occur in simple 

 udder-tuberculosis. 



I have only seen a few cases of milk-gangrene in udder- 

 tuberculosis and they were complicated with pyobacillosis. 



Wound-gangrene presupposes a tuberculous wound. 

 In this kind of wound gangrene is the rule. It develops 

 into putrid liquefaction and softening of the necrotic tuber- 

 culous area. 



General Conditions. — Blood-infection. — Tuberculo- 

 sis of the udder can induce an infection of the blood-stream 

 by lymphogenous transportation or by ulceration of a vein 

 with subsequent metastasis to the lungs, from which point 

 the condition can be more widely distributed. 



Udder-tuberculosis, which is usually caused by lung- 

 tuberculosis, can finally increase the severity of the con- 

 dition in the lungs by metastasis. 



Intoxication. — Like all tuberculosis of cows, udder- 

 tuberculosis produces no distinct initial general symptoms. 



The animal emaciates gradually and shows anaemia, de- 

 creased appetite and frequently leather-like thickening of 

 the skin and roughened hair coat. 



Finally the ansemia and emaciation become so advanced 

 that the animal dies. 



Complication with acute secondary infection can induce 

 high fever and thus bring about death of the animal. Com- 

 plication with gangrene is often accompanied by persistent 

 fever. 



Termination. — Udder-tuberculosis causes a gradual 

 progressive destruction of the udder-tissue, which may re- 

 quire from a month to a year. Destruction progresses 

 rather rapidly during the period of lactation, but more 

 slowly, often very slowly, during the non-lactating period. 



Clinical Symptoms. — The condition is a chronic one 

 and usually affects older cows which are 7 years old or 

 older. 



