VACCINE-THERAPY 167 



Bovine Tuberculosis. 



Clinical and Bacteriological Diagnosis. — Since Koch's 

 discovery of the bacillus of tubercle, our knowledge of this 

 disease as it affects man and the lower animals has ever 

 been accumulative, and although there is still much to 

 learn, probably no disease has been more fully and seriously 

 investigated than tuberculosis. 



The disease affects nearly every domesticated animal, 

 some to a greater degree than others, depending partly 

 upon the idiosyncrasies of the breed or strain, and partly 

 upon the environment of the individual, etc. It is not 

 intended here to discuss tuberculosis as it affects all the 

 lower animals, but to confine our remarks strictlv to the 

 disease as it is seen in the bovine species. 



Tuberculosis may run an acute course and terminate 

 suddenly, or it may, and usually does, develop an insidious 

 character — in fact, the degree of virulence in many cases 

 is so slight that the animal shows no indication of a removal 

 from the usual normal healthy standard. 



Recent investigation in human pulmonary tuberculosis 

 has revealed the fact that the bacillus of tubercle is not 

 such a virulent organism as the early bacteriologists led us 

 to believe — in fact, some authorities go so far as to say that 

 if no secondary infection followed the primary invasion of 

 this bacillus, the disease would lose its appalling signifi- 

 cance altogether. Certainly this teaching is in accordance 

 with our own views of such diseases as influenza and 

 distemper, where mixed infections are the order of 

 things. 



On several occasions we have isolated from the bronchial 

 discharges of cattle destroyed after reacting to the tubercu- 

 losis test streptococci rarely and staphylococci commonly, 

 and have used on a limited number of cows, which were 

 certified to be suffering from tuberculosis and which reacted 

 to tuberculin, a vaccine prepared from the bronchial and 

 tracheal discharges, combined with tuberculin and poly- 



