72 BOVINE TUBERCULOSIS AND OTHER CATTLE DISEASES. 



reacting there may be the finest appearing and best producing 

 cows in the herd. A post-mortem examination, revealing a 

 small lesion, does not convince the layman that the slaughter 

 was justified. 



New tests for tuberailosis . Of late, considerable attention has 

 been paid to certain modifications of the method of applying the 

 tuberculin test (25). Among these are the intradermo (26) 

 and ophthalmo (56) tests. Their claim to attention is based 

 on simplicity but they are as yet in the experimental stage. 



Stable sanitation and tuberculosis . Good sanitary conditions, 

 good ventilation, reasonable exercise, good climate, good food 

 and general well being are in high repute as measures for 

 restricting and preventing tuberculosis in man. In some 

 quarters there is a tendency to assume that the bovine, sur- 

 rounded by conditions that are by assumption rated as corres- 

 pondingly good, will be in a measure protected from bovine 

 tuberculosis. A true parallel does not exist, for the conditions 

 favoring the spread of bovine tuberculosis are such that the 

 best of stables in the best of climates or even no stable at all, 

 will not prevent the spread of the disease (54). Baker (4) 

 has produced some very striking evidence on the point drawn 

 from statistics concerning cattle slaughtered under Federal in- 

 spection in San Francisco. 



Tuberculin test ordinances. The object of municipal legisla- 

 tion is not primarily the eradication of bovine tuberculosis, but 

 rather to ensure a pure milk supply. The legislation, there- 

 fore, need go no farther than to ensure the exclusion of milk 

 of diseased animals by requiring that all cows pass the tuber- 

 culin test and a physical examination. Since the milk supply 

 comes largely from without the borders of the city, it would 

 be difficult, both legally and practically, to go farther than this. 

 The dairyman is thus at liberty to accept the conditions im- 

 posed for a license by the city, or to sell his milk elsewhere. 

 The plan involves no compulsory interference with property 

 rights and does not necessarily contribute to the reduction of 

 bovine tuberculosis beyond the dairies immediately affected. 



Tuberculin test ordinances are in force in a number of Amer- 

 ican cities. Probably Minnesota heads the list of states in the 



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