Animals feeding upon this vegetation may contract the
disease if the spores germinate in the body.
Another source of the virus, and one regarded by many authorities as
perhaps the most important, is the body of an animal which has died of
anthrax. It will be remembered that in such bodies the anthrax bacilli are
present in great numbers, and wherever blood or other body fluids are
exposed to the air on the surface of the carcass there the formation of
spores will go on with great rapidity in the warm season of the year. It
will thus be readily understood how this disease may become stationary in a
given locality and appear year after year and even grow in severity if the
carcasses of animals which have succumbed to it are not properly disposed
of. These carcasses should be buried deeply, so that spore formation may be
prevented and no animal have access to them. By exercising this precaution
the disease will not be disseminated by flies and other insect pests.
We have thus two agents at work in maintaining the disease in any
locality--the soil and meteorological conditions, and the carcasses of
animals that have died of the disease. Besides these dangers, which are of
immediate consequence to cattle on pastures, the virus may be carried from
place to place in hides, hair, wool, hoofs, and horns, and it may be stored
in the hay or other fodder from the infected fields and cause an outbreak
among stabled animals feeding upon it in winter. In this manner the
affection has been introduced into far-distant localities.
_How cattle are infected._--We have seen above that the spores of the
anthrax bacilli, which in their functions correspond to the seeds of higher
plants and which are the elements that longest resist the unfavorable
conditions in the soil, air, and water, are the chief agents of infection.
They may be taken into the body with the feed and produce disease which
begins in the intestinal tract, or they may come in contact with scratches,
bites, or other wounds of the skin, mouth, and tongue, and produce in these
situations swellings or carbuncles. From such swellings the bacilli
penetrate into the blood and produce a general disease.
It has likewise been asserted that the disease may be transmitted by
various kinds of insects which carry the bacilli from the sick and
inoculate the healthy as they pierce the skin. When infection of the blood
takes place from the intestines the carbuncles may be absent. It has
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