BOVINE TUBERCULOSIS. 
647 
iracticability of the plan, and has done much to educate the 
leople as to the sources of danger. The result is that many 
jwners of herds have voluntarily, and at their own expense, 
•iad the tuberculin test applied, and the diseased animals de¬ 
stroyed. The work the State has done is in this way being 
; supplemented ; and the practice of testing dairy cows is likely 
;o have a very large increase in the future, without the aid of 
compulsory measures. Once the herd is free from disease, 
t can readily be kept in this condition by exercising due pre¬ 
caution in the introduction of fresh stock. Dairymen who 
lave had unfortunate experience with the disease, have 
idopted the practice of admitting none but tested cows to 
:heir purified herds. This practice, if uniformly adopted, 
would very soon render the dairy herds of Iowa free from 
:uberculosis. If, in addition to these precautions, similar 
vigilance were exercised over the introduction of breeding 
stock to the herds, the chief sources of infection could thus 
be shut off. If restrictive measures of this kind were applied 
to these two classes of cattle, practically all- the cases of 
tuberculosis in the State would soon be found, and its ravages 
reduced to the minimum. The measures adopted in a few 
score of dairy herds in the State, if applied to the remainder, 
would go very far toward eradication. It is possible to reach 
most important practical results without the expenditure of 
large sums of money or the sacrifice of important interests. 
All animals suffering from the disease in any of its stages 
should be at once removed from contact with other cattle. It 
is our judgment that any plan which contemplates keeping 
tuberculous animals on the farm, and attempting to avert 
danger by segregation and other like precautionary methods, 
will defeat its own ends. The less the number of possible 
sources of infection in the country, the more successful will 
be the efforts at eradication. Buildings where tuberculous 
animals have been confined are to be regarded as infected, 
and no healthy animal should be assigned quarters in such en¬ 
closure till thoroughly disinfected. 
It is true, a single test may not in every instance free the 
•entire herd. After-infection may take place. It would be 
