RURAL VETERINARY SECRETS 123 



been incredvilous, antagonistic, or prejudiced against the tuberculin 

 test by misinterpreting published statements, by incorrect unsub- 

 stantiated, or exaggerated reports, and by alleged injurious effects 

 to healthy cattle. 



Law has clearly stated the question when he says ; 



"Many stock owners still entertain an ignorant and unwar- 

 ranted dread of the tuberculin test. It is true that when recklessly 

 used by ignorant and careless people it may be made a root of evil, 

 yet as employed by the intelligent and careful expert it is not only 

 perfectly safe, but it is the only known means of ascertaining ap- 

 proximately the actual number of affected in a given herd. In most 

 infected herds, living under what are in other respects good hy- 

 gienic conditions, two-thirds or three-fourths are not to be detected 

 without its aid, so that in clearing a herd from tuberculosis, and 

 placing both herd and products above suspicion, the test becomes 

 essential. 



"In skilled hands the tuberculin test will show at least nine- 

 tenths of all cases of tuberculosis when other methods of diagnosis 

 will not detect one-tenth." 



It is perfectly natural that there should be objection to its 

 use among those who are not acquainted with its method of prepa- 

 ration or its properties, but it is difficult to explain the antagonism 

 of farmers who are familiar with the facts connected with the manu- 

 facture and use of tuberculin. Probably the most popular objec- 

 tion to tuberculin is that it is too searching, since it discovers cases 

 in which the lesions are small and obscure. While this fact is ad- 

 mitted, it should also be borne in mind that such a small lesion to- 

 day may break down and become widely disseminated in a rela- 

 tively short period. Therefore, any cow affected with tuberculosis, 

 even to a slight degree, must be considered as probably dangerous, 

 not only to the other animals in the herd, but also to the consumer 

 of her products. In connection with the above test, tuberculin is 

 now applied to the eye and injected interdermally to aid in diagnos- 

 ing tubercular subjects. 



