Bull. 56, Hygienic Laboratory. 
The subject of the picture was kept under observation about two years. She expelled tubercle bacilli per rectum, but 
her milk remained free from infection until about two weeks before she was killed. Her udder suddenly increased 
enormously in size and the material obtained from it was found to contain numerous tubercle bacilli. This cow is 
a rare illustration of the fact that acute tuberculosis may develop suddenly in the udder of a tuberculous cow and 
thus make her milk extremely dangerous. The next picture shows the condition of the udder found on autopsy. 
