82 MILK HYGIENE 



respect to the first forms of tuberculosis mentioned, it 

 must be microscopic as well, for tubercle bacilli may be 

 found in the milk, in the uterine secretion and some- 

 times in the excrement when the clinical symptoms are 

 such as merely to arouse suspicion. Such an examina- 

 tion of the herd, to be efficient, should occur frequently, 

 at least every fortnight, since this disease, and esjoecially 

 tuberculosis of the udder, may develop materially in this 

 time. ^2 



It can hardly be stated, in general, how strict the 

 regulations regarding tuberculous animals should be. 

 In some countries it is only forbidden by law to use milk 

 unboiled from cows with udder tuberculosis. Milk from 

 cows with tuberculosis of the uterus, of the intestines 

 and miliary tuberculosis, and also from cows that are 

 cachectic, should not be permitted to be sold. It would be 

 best, if it could be arranged, to allow the sale of milk 

 from herds in which there are tuberculous animals only 

 under declaration of the condition of the herd; but on 

 account of the great extent of tuberculosis no such 

 requirement has been made. It is a reasonable and, at 

 the same time, an absolutely necessary requirement that 

 the so-called " nursery milk," milk intended especially 

 for small children and invalids, should come from a 

 herd which is entirely free from tuberculosis, that is, a 

 herd composed of cows none of which have reacted to 

 the tuberculin test. 



Tests. — The discovery of tubercle bacilli in the milk 

 of individual cows with advanced udder tuberculosis and 

 in the discharge from the uterus, is usually easy. A 

 small quantity of the fluid or a little flake or lump is 

 spread upon a cover glass, it is fixed in the usual way in 

 the flame and then stained according to one of the 

 methods given below. 



^^ This relates to herds known to be infected. [L. P.] 



