274 TUBERCULOSIS. 



responded, she is for some time protected from a second test. A 

 dishonest dealer, therefore, may inoculate his cows privately and 

 then put upon the market all those that respond to the test, knowing 

 that for some time they will not again respond. One thing is 

 certain. No farmer can be confident of keeping his herd free from 

 this disease unless he can be assured by the tuberculin test that he is 

 purchasing animals freed from every suspicion of the disease. 



Second: He must prevent his cattle from associating with 

 strange cattle. If put out to pasture they must be kept by 

 themselves and guarded against chance contact with strangers. 

 Common watering troughs, in which miscellaneous cattle are 

 watered, must be shunned. 



Third: He must not feed his calves upon milk from other 

 herds. The way in which this is most commonly done is by the use 

 of skim milk returned from a creamery or a separating station. 

 From such a creamery the farmer does not get back his own milk, 

 but always milk from another source, and, if there be a few cases 

 of bovine tuberculosis of the udder in the neighborhood, the bacilli 

 from these animals will soon be distributed through the separating 

 station over the entire region contributing to the station. This is 

 not mere theory, but positively ascertained fact. To such milk is to 

 be attributed the large amount of tuberculosis among swine in 

 recent years. The only safe procedure is for the farmer either to 

 bring up his calves on the milk from his own healthy herd or to 

 insist that all milk fed to them shall first be subjected to the process 

 of pasteurizing or boiling. So convinced are the agriculturists in 

 Denmark that this mixed milk is the cause of much of the bovine 

 tuberculosis, that a law has been passed forcing the pasteurization 

 of all milk which is thus brought to creameries for separation of the 

 cream. The farmer is thus protected from the tuberculosis of his 

 neighbors' herds. 



Treatment of a Tuberculous Herd. There appear to be four 

 general methods of treating a herd after this disease breaks out in it: 



i. All advanced cases which are recognized as dangerous to 

 the public, including all cases of udder tuberculosis, may be removed 

 and the animals destroyed, the others being left undisturbed. 



