tional Governments can be
successful only when the same principles are adopted and carried out as
here recommended for individual stables. It is then a difficult
undertaking, simply because the contagion is generally widely disseminated
before any measures are adopted, and because a great majority of cattle
owners will never report the existence of the disease. Regulations must
therefore be enforced which will insure the prompt discovery of every herd
in which the disease appears, as well as the destruction of all diseased
and exposed animals and the thorough disinfection of the premises.

To discover pleuropneumonia sufficiently early for this purpose, the
district supposed to be infected should be clearly defined and inspectors
should be constantly employed to inspect every herd in it at least once in
two weeks, or, better, once a week. No bovine animal should be allowed to
go out of the defined district alive, and all which enter it should be
carefully inspected to insure their freedom from disease. As an assistance
to the discovery of diseased herds, every animal which, from any cause,
dies in the infected district and every animal which is slaughtered, even
if apparently in good health, should be the subject of a careful
post-mortem examination. Many affected herds will be found in this way.

In addition to these measures it is also necessary to guard against the
removal of animals from one stable to another and the mixing of herds upon
common pastures or in the public highways. The object must be to isolate
every individual's cattle as completely as possible, or otherwise a single
affected animal may infect a dozen or more herds. To prevent surreptitious
sale or trading of cattle, each animal must in some way be numbered and
recorded in the books kept by the official in charge of the district. In
the work of the United States Department of Agriculture a numbered metal
tag was fastened to each animal's ear and index books were so arranged that
with a number given the owner could be at once ascertained, or from the
owner's name the cattle for which he was responsible could be at once
learned. In this way, if an animal was missing from a stable, the fact
became apparent at once, or if one too many was found in a stable the
number in its ear would indicate where it came from.

When pleuropneumonia is discovered by these means, the entire herd should
be slaughtered as soon as the formalities of appraisement can be arra