THIRTEENTH ANNUAL YEAR BOOK— PART XI 



571 



No. 5. — A lonji slanaiiiK iulvaiic.^d case of tuljerculusi.s, vviLh laryo tuberculous 

 swellings in the udder. A year before the above picture was taken 

 the cow was discovered to have udder tuberculosis. This discovery 

 was made by injecting some of her milk into guinea pigs ; there was 

 nothing in the appearance of external condition of the udder at first 

 to show that it was diseased. 

 How very dangerous cows like the one in the picture are may be 

 judged from the fact that calves that are permitted to drink milk 

 from tuberculous udders only a single time are almost certain to 

 have tuberculosis. A small amount of milk from cows like those In 

 the above picture No. 4, mixed with the milk of other cows, will 

 make the whole of it dangerous for both persons and lower animals. 



