REACTION AFTER TUBERCULIN 355 



cases. The respiration and pulse often become increased in relation 

 to the rise in temperature, at other times these physiologic functions 

 show no marked changes from the normal, Sometimes about the 

 sixth to the eighth hour after the injection the animal suffers from 

 some weakness and lack of appetite. Trembling of the muscles may 

 also be observed. The secretion of milk during a positive reaction 

 becomes reduced, generally between 3 and 8 per cent., exceptionally 

 as high as 13 per cent. There is no direct relation between the 

 intensity of the reaction and the intensity of the tubercular process, 

 except that much advanced cases of tuberculosis in weakened animals 

 give a weak reaction. 



The tuberculin test has, as a rule, no lasting ill effect, except in 

 very weak animals with advanced tuberculosis, where the test may 

 be followed by a more or less permanent rise in temperature and a 

 more rapid course of the tubercular process. Healthy animals do 

 not react or only very slightly to the ordinary diagnostic doses or to 

 even larger doses of tuberculin; this is also true of animals suffering 

 from other diseases. 1 It should also be noted that a positive reaction 

 can only be expected after the tubercular infection has existed for a 

 certain minimum time. Nocard showed by experiments that at least 

 two weeks must elapse between the time of infection with moderate 

 doses of tubercle bacilli and the time of the first appearance of a 

 positive tuberculin test. McFadyean found a positive reaction in 

 eight days after very large doses of infecting bacilli. After natural 

 infections it requires doubtless a much longer time before a positive 

 test can be obtained. The limits given above all refer to infection 

 by injection. According to Nocard and Rosignol, infection through 

 the intestinal tract is followed by a positive tuberculin reaction after 

 thirty-two to forty-eight days; while infection by inhalation leads to 

 positive reactions after nineteen to thirty-two days. 



Nocard regards a rise of 1.4 F. as insignificant; one from 1.4 to 

 2.5 F. (always provided that it occurred in the typicaj gradual 

 manner) as suspicious and requiring re-testing at the end of a month; 

 while a rise of 2.5 to 5.4 F. absolutely indicates the presence of 

 a tubercular process in the animal tested. 



The Eighth International Veterinary Congress (1905, Budapest), 

 adopted the following resolutions in regard to the tuberculin test: 



1. The preparation and supply of tuberculin should be controlled 

 by the State. 



2. No animal whose temperature exceeds 39.5 C. (103 F.) is a 

 fit subject for the tuberculin test. 



3. A rise of temperature to above 40 C. (104 F.) in any animal 

 whose temperature at the moment of injection was below 39.5 C. 

 (103 F.) is to be regarded as a positive reaction. 



1 The tuberculin test is, of course, not applicable in the presence of high fever no matter to 

 what it may be due. 



