UDDER-TUBERCULOSIS 95 



6.6 per cent., did not show tuberculosis of the lungs, accord- 

 ing to the post-mortem protocol. These were cases of pri- 

 mary udder-tuberculosis which were obviously caused by 

 infection through the teat canal, since the udders presented 

 no wounds. 



Since this type of primary udder-tuberculosis can be 

 present along with tuberculosis of the lungs, this figure is 

 somewhat too small. It should probably not be too much 

 increased, however. If we estimate, that ca. 10 per cent, 

 of all cases of udder-tuberculosis are primary and caused 

 by infection through the teat canal I believe that we shall 

 be more nearly correct. 



It is absolutely impossible to distinguish primary from 

 embolic tuberculosis of the udder by post-mortem examina- 

 tion. Primary tuberculosis following infection through the 

 teat canal presented no specific post-mortem picture, but 

 the lesions are the same as those of embolic udder 

 tuberculosis. 



Likewise, localization of lesions in one quarter is of 

 no special significance, since embolic tuberculosis can begin 

 in any quarter. Further, it appears that the condition can 

 easily spread from one quarter to another by teat-canal 

 infection. The infection can also be extended by the lymph 

 stream, but only in the direction in which the lymph flows 

 from the fore quarters toward the hind quarters. 



Of the nine cases of primary udder-tuberculosis induced 

 by teat-infection named, five cases showed only one quarter 

 affected: the left posterior quarter in two cases; the left 

 anterior quarter in one case ; the right posterior quarter in 

 two cases; three cases showed two quarters affected: both 

 posterior quarters in two cases ; the left posterior and right 

 anterior quarter in one case; one case showed all four 

 quarters affected. 



Primary Udder-tuberculosis hy Infection of Wounds. — 

 This is exceptionally rare. I have only seen a single case 



