Tuberculosis in Line Stock. 
5 
of tuberculosis, a largo part of the milk consumed daily is not pas¬ 
teurized, and some of the milk so treated is not always made entirely 
safe. 
TUBERCULOSIS A DECEPTIVE DISEASE. 
If tuberculosis were similar to foot-and-mouth disease in cattle, 
swine, and sheep, which causes rather spectacular symptoms, it 
would arouse immediate alarm among the live-stock owners, who 
would insist upon its immediate eradication; but because it is gen¬ 
erally slow in developing and its symptoms commonly are not easily 
recognized from the general outward appearance of the animals, 
many people believe that it does comparatively little damage among 
live stock. Contrary to such opinions, however, the loss from tuber¬ 
culosis is one of the heaviest taxes imposed upon our live-stock in¬ 
dustry, amounting, probably, to at least $40,000,000 a year in the 
United States. 
PREVALENCE OF TUBERCULOSIS. 
In every State and Territory in the Union there is some tubercu¬ 
losis among cattle and swine, though the degree varies considerably- 
In some States it probably exists quite extensively, the percentage 
varying from 5 to 30 per cent of the cattle population, while in cer¬ 
tain others investigations indicate that less than 1 per cent of the 
total of beef and dairy cattle are tuberculous. 
Tuberculosis is known to exist also quite extensively among cattle 
and swine in all the European countries; in fact, no part of the world 
is known to be free from it absolutely. There are, however, some 
restricted regions where its presence is not known, or it exists to 
but a very moderate degree. 
Until cattle from the eastern part of the United States were intro¬ 
duced into the Middle Western, Western, and Southern States, 
tuberculosis among live stock in those regions was unknown so far 
as we know. The disease at that time was confined to the herds 
east of the Allegheny Mountains. It was known then that a consid¬ 
erable percentage of herds in those States were affected, but live¬ 
stock owners were not inclined to consider tuberculosis as of very 
great economic importance or dangerous to human health. Therefore 
very little progress was made in its eradication. As the Central and 
Western States became settled and cattle were moved westward the 
disease spread much more rapidly than is generally realized. The 
spreading in those areas is due, of course, to the fact that the live¬ 
stock industry occupies a more important part in agriculture than 
in the Eastern States. Cattle are traded in more extensively and are 
continually being shipped and trailed from State to State and from 
farm to farm. 
