BOVINE TUBERCULOSIS 



BY HERBKRT IF. LAMSON 



Everybody knows that consumption is one of the most serious 

 diseases which afflict mankind. It is a common statement 

 that one seventh of all deaths are due to it in some of its varied 

 forms. Its prominent characteristics are the destruction of 

 portions of the lungs or intestines and the rapid or gradual 

 wasting of the other tissues with the accompanying loss of 

 vital strength, ending in death. Hence the appropriateness of 

 the name consumption. The above mentioned symptoms are 

 the most striking manifestations of a general diseased condi- 

 tion known as tuberculosis. It is called tuberculosis because 

 in the diseased parts are found new growths in tlie form of 

 rounded masses or nodules, known as tubercles. 



This disease affects the lower animals as well as man, the 

 bovine family being especially liable to its attacks. 



CAUSE 



One of the most significant facts in a consideration of tuber- 

 culosis is its cause. Many diseases are caused by the subjection 

 of the system as a whole or of particular organs to unfavor- 

 able physical conditions, such as climatic conditions, changes 

 of temperature, exposure, undue or improper exercise, deficient 

 or improper food, etc., which interfere with the normal 

 function and result in dis-ease. Another and veiy important 

 class of diseases are known as germ diseases ; they are caused 

 by the presence of germs, or micro-organisms. These micro- 

 organisms are now generally recognized as minute plants (the 

 smallest and simplest members of the vegetable kingdom) and 

 are called bacteria. (For a general description of bacteria, 

 see Bulletin No. (y^^ pp. 15S-164). 



The disease-producing bacteria, introduced in various ways 

 into the animal system, cause changes in the tissues or organs, 

 which result in the manifestation of the characteristics or 



