Tuberculosis. 509 



Bang, Eber and Pearson, based on a very extensive experience, 

 would indicate that the tuberculin test is not forbidden by the 

 parturient condition. Eber concludes that unless the initial tem- 

 perature materially exceeds 39.5° C. (103° F.) the parturient 

 state is no barrier to successful testing. My own experience, on 

 the contrary, is that a considerable proportion of parturient cows 

 give a reaction when the initial temperature did not exceed 

 103" F., and when no sign of tuberculosis could be found. As 

 an example, a cow in high condition, with an initial temperature 

 of 102.8° F., rose gradually from the eleventh hour after injec- 

 tion and reached 106.3° by the eighteenth, a rise of 3.5°. From 

 the record she was not due to calve for three months, but a fort- 

 night later, when already killed and laid open, she showed all 

 the signs of parturition, a fully matured calf, and not a trace of 

 tubercle. This is far from unusual, and I am convinced that 

 many errors will be avoided by refusing to condemn parturient 

 animals or those within a couple of weeks before or after parturi- 

 tion on the tuberculin test alone. 



Reliability of the Tuberculin Test. Even in the most careful 

 hands the tuberculin test cannot be held to be infallible. A cer- 

 tain very small proportion of cows react without the recognition 

 of any tubercle post mortem, some because of other bodily condi- 

 tions, like parturition or abortion, but in skilled hands these may 

 be ignored in ordinary sanitary work. Pearson claims to have had 

 but 8 such cases in 4400 cows that gave a tjrpical reaction. He 

 suspects that some of these even had undiscovered tubercle, and 

 Nocard thinks that all such cases are to be explained in this way. 

 On the other hand a very few really tuberculous animals fail to 

 react, some in connection with advanced disease, some because of 

 repeated previous testing, and some because of the introduction 

 of antipyretic agents into the system, but such cases can either be 

 detected and controlled or are so infinitesimal in numbers, that 

 they can safely be ignored in sanitary work. In skilled hands, 

 the tuberculin test will show at least y% ths of all cases of tuber- 

 culosis, when other methods of diagnosis will not detect x^t\i. 

 See above case of herd where objective symptoms showed noth- 

 ing, yet tuberculin condemned half the mature cattle, and post 

 mortem confirmed this, the skeptical veterinarian being judge. 



