NINTH ANNUAL YEAR BOOK— PART IX 391 
the pens before they are sold; and any lots that present symptoms of 
such diseases as scab, cholera, etc., are held for final disposition according 
to the regulations of the Secretary of Agriculture. 
These regulations are formulated for the purpose of preventing the 
spread of disease, and consequently vary according to the character of 
the disease and its mode of transmission; and the regulations relative to 
any particular disease may be changed from time to time as the condi- 
tions change. For illustration, cattle or sheep that are found upon yard 
inspection to be affected with scabies, may be slaughtered at the local 
abattoirs; for these are diseases of the skin due to a small parasite, some- 
what like a louse, and the flesh is not affected except in the latter stages 
of very severe cases. But scabby cattle are prohibited from being shipped 
to other public yards until after they have been dipped; and where they 
are to be shipped to country points for feeding, stocker or breeding pur- 
poses, they must be dipped twice at about ten days apart. This is done 
to prevent these diseased animals conveying the disease to those locali- 
ties that are now free. The regulations relative to hig cholera and its 
allied diseases, prescribes that no swine can be shipped from public yards 
to country points for any purpose. 
The reasons for this are, that these diseases are contagious and healthy 
S"w ine may contract them by being yarded in pens that have recently held 
diseased hogs. Owing to the fact that more or less diseased swine are 
being continually shipped to market, the public yards are always infected 
so that all hogs being yarded in them are exposed to the germs of these 
diseases, and experience has demonstrated that where hogs have been 
taken from public yards to country feed lots, they usually contract one 
or more of the diseases and more or less of them die; thus making it not 
only a poor investment for the owner, but also a center of infection for 
the spread of the disease; and, therefore, a source of danger to all his 
neighbors who own swine. Numerous instances are on record where 
cholera has been carried into non-infected territory and at times several 
hundred miles from the yards where the disease was contracted. 
The general public may think that no one would take the chances of 
carrying a contagious disease like hog cholera, sheep scab, or cattle mange 
from the yards to their stock at home, but it should not be forgotten 
that there are always men who do not know that these diseases and oth- 
ers — a more dangerous class, who think that they are wise enough to do 
those things that good prudent business men would not consider wise or 
safe, and the public needs protection from these classes of individuals. 
This protection is afforded to a greater or less degree by the extension of 
the meat inspection system to cover this work. So much for the branch 
covering the control of contagious diseases. 
The stock that is sold for slaughter in the city where the inspection 
is carried on are inspected again — as they go to the scales to be weighed 
— for such diseases as actinomycosis, tuberculosis, abcesses, injuries, etc., 
and such animals as present any of these diseases sufncient to make prob- 
able that their flesh will be unwholesome for food, are tagged vrith a 
metal tag bearing a number so that the animal may be identified when it 
reaches the slaughter house. Then the inspector doing the post mortem 
