846 Report of the Tuberculosis Commission, [feb., 



containing an account of certain experiments carried out 

 regarding the infectivity of the milk and faeces of naturally 

 infected tuberculous cows, i.e., cows that have contracted the 

 disease in the ordinary way. 



In the Second Interim Report the Commissioners expressed 

 the opinion, as a result of their investigations, that a very 

 considerable amount of disease and loss of life, especially 

 among infants and children, must be attributed to the con- 

 sumption of cow's milk containing tubercle bacilli. 



Tuberculosis involving the udder is comparatively common 

 in cows., and in such cases their milk always contains tubercle 

 bacilli, and is therefore dangerous for human beings con- 

 suming it. It was, however, undecided what was the danger, 

 if any, attaching to the milk of tuberculous cows in which 

 the udder presents no evidence of disease, but a number of 

 observations and experiments bearing on this point have now 

 been made. The experiments were made with the milk of 

 cows which had contracted the disease in the natural way. 



In natural tuberculosis in the cow, cases which show such 

 obvious symptoms of the disease as emaciation and cough 

 should be considered separately from the cases in which there 

 are no such signs and in which the disease is to be recog- 

 nised during life only by means of the injection of tuberculin. 

 None of the cows investigated showed any sign of disease of 

 the udder during life, and in all, after slaughtering, the udder 

 was carefully examined for tuberculous lesions and tubercle 

 bacilli. No tuberculosis was found except in one case, in 

 which one-quarter of the udder showed four small nodules. 

 These could not possibly have been detected during life. 



It was found that the milk of the cows obviously suffering 

 from tuberculosis contained tubercle bacilli whether the milk 

 was obtained in the ordinary way or was withdrawn from 

 the teat by means of a sterilised catheter. The presence of 

 tubercle bacilli in the milk of cows clinically recognisable 

 as tuberculous confirms the opinion expressed in the Second 

 Interim Report that the milk of such cows must be considered 

 dangerous for human beings. 



The experiments which the Commission have carried out 

 with regard to the infectivity of the faeces of tuberculous cows 

 were dictated by knowledge of the fact that dirt of various 



