384 BOAED OF AGRICULTURE. [Pub. Doc. 



"TUBERCULOSIS." 



Tiilierculosis in cattle is a subject of equal importance, not 

 only to the agriculturist but to the public generally. Its eradi- 

 cation from the animals from which we derive so large a portion 

 of our nutrition is of the utmost importance from the stand- 

 point of public health. The insidious nature of the disease 

 has much to do with the comparative slowness with which pro- 

 fessional and public attention has been directed to it. 



In the middle ages tuberculosis in animals was recognized as 

 contagious, and laws were passed prohil)iting the use of the 

 carcass for food, which laws have remained in force in Italy and 

 Spain up to the present time. In the sixteenth century it was 

 confounded with syphilis, and at the end of the eighteenth 

 century with glanders. The propagation by contagion in herds 

 was recorded in Germany by Ruhling in 1774 and by Krunitz 

 in 1787, and more recently by Spincla, Zanngers and others. 

 In France the same was claimed by Fromag, Huzard, Lafosse, 

 Dupont and Crucel. 



The manifest tendency of the disease to run in families, and 

 to develop under special unwholesome conditions of life, serves 

 to weaken the belief in contagion, and in central and western 

 Europe such belief had become practically extinct among medi- 

 cal men, when their attention was recalled to the subject by 

 scientific inoculation of tuberculosis in rabbits and guinea pigs 

 by Villemin in 1865. 



No practical addition to our knowledge of the disease was 

 made until Koch discovered in 1882 the bacillus tul^erculosis, 

 since which the identity of the disease in man and animals has 

 been fully established. 



Prevalence. 

 Owing to the facts that up to within a very short time we 

 have been unal)le to make a reasonably sure diagnosis, and that 

 we have had no systematic inspection of our abattoirs and 

 slau2:hter houses, there arc no avaihible statistics as to the 

 prevalence in our immediate vicinity. All we can do is to 

 reason by analogy from such statistics as are obtainable. The 

 following abattoir statistics, showing the percentage of tuber- 

 culous animals, are of value in this connection : Prussia, 6.3 



