1126 New York State Breedeks' Associatiott 



THE UNDERLYING PRINCIPLES IN THE CONTROL OF INFECTIOUS 



DISEASES OF ANIMALS 



Dr. V. A. Moore, Dean State Veterinary College, 



Ithaca, N. Y. 



When Commissioner Hnson invited mo to speak before this 

 association, it occurred to me that j^erhaps the most helpful 

 thing that I could do would be to discuss the essential facts and. 

 underlying principles in the control of infectious diseases of 

 animals. Few of us realize the enormous loss to the live stock 

 industry because of infectious diseases. Professor Willcox esti- 

 mated a few years since that bovine tuberculosis costs this state 

 $5,000,000 annually. Dr. Williams in a recent report of his 

 studies of cattle diseases places the toll from infectious abortion 

 and sterility in cattle at from 5 to 10 per cent, annually. 

 Glanders in horses, anthrax, rabies and hog cholera each exact 

 a heavy toll from the live stock owners as well as from the state 

 treasury. 



For many centuries this class of diseases was viewed with 

 mystery. At the present time infections are considered by many 

 stock owners as misfortunes entirely beyond their power to pre- 

 vent or control. The reasons for this are not difficult to explain, 

 because as yet our people have not learned to study the habits 

 or to follow the life history of invisible microscopic organisms 

 that prey upon higher forms of life. 



With general diseases duo to improper care of the body it is 

 easier to understand that there is a direct relation between cause 

 and effect, although with these there is still much to be learned. 

 The infectious diseases, however, present a different phenomenon. 

 They are the direct result of the invasion of the body with cer- 

 tain definite living plants or animals. They are to be likened to 

 a crop of grain, which is the direct outcome of the planting in 

 suitable soil of the seed of the crop desired. As the sowing of 

 wheat in suitable ground gives rise to a crop of wheat, so the 

 sowing of the bacteria of anthrax, glanders or tuberculosis into 

 the tissues of the animal body will give rise to those diseases. 



The facts that are necessary to understand the appearance, 

 course and disappearance of any given infectious disease pertain 

 largely to the germ producing it. The external world is literally 



