INFLUENCE OF DISEASE UPON MILK 91 



physical examination in addition to a tuberculin test is 

 necessary because the tuberculin test alone will not detect 

 all cases of tuberculosis. Ostertag, for instance, tested 

 with tuberculin nine cows affected with udder tubercu- 

 losis and two failed to- react. The adoption of such a 

 plan, however, immediately upon the introduction of 

 dairy inspection in districts in which tuberculosis is com- 

 mon will meet with many practical difficulties. Few 

 dairymen in such districts are able to bear the expense 

 of disposing of non-clinical reactors as well as clinical 

 cases and of replacing them with healthy cows, even 

 with state assistance ; and the state would not have suffici- 

 ent funds to render the assistance provided by present 

 laws if such a plan was generally adopted. Difficulty 

 would also be experienced in replacing the reacting cattle 

 with animals free from tuberculosis, and this would in- 

 crease with the number of herds included in the inspection. 

 The opposition of the dairymen concerned would be 

 very generally incurred and there would not exist that 

 friendly cooperation between the inspector and dairy- 

 man which is necessary to insure the most satisfactory 

 results. A careful and thorough physical examination 

 repeated at intervals is next in the order of effectiveness. 

 By this method those cows can be discovered which are 

 the most concerned in the contamination of milk with 

 tubercle bacilli. Such an examination should include a 

 careful inspection and palpation of the udder and supra- 

 mammary lymph glands ; inspection of the milk in each 

 quarter; palpation of the other superficial lymph glands; 

 examination of the general condition of the animal; in- 

 spection for nasal discharge; examination for cough; 

 examination of the respiration; auscultation of the lungs ; 

 examination of the digestive tract, especially for chronic 



