CHAPTER XXII 



COMMON AILMENTS OF CATTLE* 



While it is not intended that this volume shall be a book on 

 veterinary practice, it is well known that the regular herdsman 

 or caretaker should be able quickly to recognize when his charges 

 are out of health and be able to treat the commoner or simpler 

 afflictions. These considered here are those most frequently 

 to be dealt with. 



TUEEECULOSIS 



Tuberculosis is a widespread infectious disease caused by the 

 bacteria of tuberculosis affecting man and lower animals. 



Occurrence — Tuberculosis exists in all civilized countries. 

 In America the disease was introduced with early importations 

 of cattle and has gradually spread until no section of the country 

 is free from it. The exact percentage of tuberculous animals 

 in any country is unknown, but the relative number has been 

 determined by tuberculin testing and by post-mortem examina- 

 tions in abattoirs. The Secretary of Agriculture, in his report for 

 1908, estimated that one per cent of beef cattle and ten per cent 

 of dairy cattle were tuberculous. 



Importance. — Tuberculosis is to-day the most serious prob- 

 lem confronting the livestock industry. The disease is prob- 

 ably not on the increase among cattle, but is becoming more 

 prevalent among swine and poultry. Thousands of infants and 

 young children receive cow's milk as their chief diet and it is 

 usually consumed in the raw state. Milk from cows affected 

 with tuberculosis often contains living virulent bacilli of tuber- 

 culosis. Children consuming this milk may develop tuberculosis, 

 which is frequent cause of death. Scientific investigations show 

 that a certain percentage of human tuberculosis is of bovine 

 origin, the germs being transferred through the use of milk, 

 butter, and cheese, or improperly cooked meat of animals. 



Nature of Tuberculosis. — Tuberculosis is, as a rule, a 



chronic, insidious disease which spreads slowly from animal to 



animal in a herd until most of them are affected. Tuberculosis 



* Written by Dr. W. L. Boyd. 



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