X... 4.] CATTLE COMMISSIONERS' REPORT. 515 



The milk from tuberculous cows with apparently healthy udders 

 may be dangerous, and is always suspicions. 



In the year book issued by the United States Department of 

 Agriculture for the year 1894 the following occurs : — 



The dilemma in which the demands of public health have put the 

 owner of cattle, as well as the health officer, has already been stated. 

 The following statements referring to this subject are based upon a 

 careful study of the distribution of the disease in a large number of 

 animals. It needs to be emphasized here that arguments deduced 

 from the superficial examination of a carcass and the simple determi- 

 nation of the presence or absence of tuberculosis are worth -little or 

 nothing in attempting to solve the problems presented by the sanitary 

 side. Only a thorough survey of the entire distribution of the tuber- 

 culous deposits in animals furnishes us with approximately correct 

 data. 



The flesh of those infected cattle in which the disease is restricted 

 to one or two primary foci must be regarded as entirely harmless 

 and of full nutritive value. Even in advanced cases, which should 

 always be rejected, the glands embedded in the muscular tissue are 

 found infected only occasionally. 



The condition of the milk in different stages of the disease is a 

 question of much greater importance, and demands the most careful 

 consideration. We may, for convenience and clearness, typify three 

 stages : — 



1. In the earlier stages of the disease, provided the udder is 

 normal, the milk is free from tubercle bacilli. 



2. In the more advanced stages, provided the udder is normal, 

 the milk may or may not contain tubercle bacilli. If the disease has 

 become generalized, the indications are that at some time or other 

 tubercle bacilli may pass into the milk. This passage is revealed at 

 the autopsy by disease of the glands or the udder. The indications 

 are that this passage is largely temporary, perhaps lasting only u day 

 before the tubercle bacilli are caught up and filtered out into the 

 lymphatic system. The indications are, furthermore, that compara- 

 tively few bacilli pass through the udder. The udder itself does 

 not favor their development there, and the closest inspection fails to 

 reveal any augmenting foci of disease. These statoments are based 

 upon careful examination of slaughtered cattle and the thorough test- 

 ing of the milk from advanced cases. 



•3. When the udder is affected in any stage of the disease, a most 

 grave condition is presented. Tuberculosis of the udder in most 



