Issued August 31, 1916. 



U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF ANIMAL INDUSTRY. 

 A. D. MELVIN, Chief of Bureau. 



SPECIAL REPORT 



DISEASES OF CATTLE. 



"The Tuberculin Test" 



Specificity of tlie Tubercalin Reaclion. 



Concerning the use of tuberculin as a di- 

 agnostic agent. Dr. D. E. Salmon concludes: 



(1) That the tuberculin test is a wonder- 

 fully accurate method of determining if an 

 animal is affected with tuberculosis. 



(2) That by the use of tuberculin the 

 animals diseased with tuberculosis may be 

 detected and removed from the herd, there- 

 by eradicating the disease. 



(3) That tuberculin has no injurious ef- 

 fect upon healthy cattle. 



(4) That the comparativelj' small number 

 of cattle which have aborted, suffered in 

 health, or fallen off in condition after the 

 tuberculin test were either diseased before 

 the test was made or were affected by some 

 cause other than the tuberculin. 



The most reliable means of diagnosis in 

 the living animal is by the use of tuberculin. 

 The subcutaneous method is the most cer- 

 tain method of using it, although other 

 methods, such as the conjunctival (ophthal- 

 mic) and the intradermal method have cer- 

 tain advantages.— (Moore.) 



Concerning the reliability and efficiency of 

 the tuberculin test the following resolutions 

 were adopted by the A. V. M. A. of September 

 10, 1908: 



"That the experience which has been ac- 

 cumulated in great amount since the dis- 

 covery of tuberculin shows conclusively and 

 novir more clearly than ever before, that it 

 affords an accurate and reliable means for 

 diagnosing tuberculosis in cattle. The per- 

 centage of errors from the use of tuberculin 

 when properly applied is so small as to be 

 of no moment when compared with the vast 



GH, KiCKMAN, LAW, 

 , PEARSON, 

 ;OWER. 



N, 1916, 



IjO- VE-niNivii^/iN X riviiN JL11->TG OFFICE. 



1916. 



