68 BOVINE TUBERCULOSIS AND OTHER CATTLE DISEASES. 



In most cases great expense has been incurred by the dairymen, 

 with Httle permanent benefit. Tuberculosis in general has 

 kept pace with the efforts directed against it, and in only a 

 few states can it be claimed that substantial progress is being 

 made in its eradication. Dairymen have, for almost a genera- 

 tion, been harassed by agitation over the subject and tjieir atti- 

 tude towards public health measures is one of indifference or 

 open hostility. City milk supply is derived from such scattered 

 sources that effective administration is difficult. Then, too, the 

 individual cows comprising the herds are constantly changing 

 as they dry off and are replaced by fresh cows. Coupled with 

 this it should be noted that the majority of dairymen persist- 

 ently ignore precautions against introducing the disease. Under 

 these conditions the temptation is great to resort to bribery in 

 some cases, or to legal measures for the purpose of invalidating 

 the ordinance. The circumstances are such as to encourage 

 laxity in the enforcement of tuberculin test ordinances. A 

 sharp distinction should be drawn between the meanings of 

 the expressions ' ' in force ' ' and ' ' enforced ' ' as applied to an 

 ordinance. 



Physical exami7iation. While some advanced cases of tuber- 

 culosis can be recognized by physical examination, such an 

 examination will reveal but a small percentage of the cases 

 capable of disseminating infection. 



The idea of inspecting dairy herds by physical examination 

 alone is based upon the belief that a physical examination is 

 capable of indicating the seriously diseased animals. The evi- 

 dence accumulated from post-mortem examinations of dairy 

 cattle, and from the bacteriological examination of feces, con- 

 troverts the truth of the assumption. If a physical examination 

 is to be of use, it must be so searching as to permit the detec- 

 tion of all those animals having open lesions in the respiratory 

 and alimentary tracts. Such results are not obtainable. Among 

 the dangerously tubercular animals may be found at post- 

 mortem examination the best looking cows in a herd. The 

 condition of flesh of an animal is worthless as a guide. The 

 good dairy cow certainly is emaciated at times, and this in 

 conjunction with an old coat of hair gives a miserable appear- 



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