Orleans County monitor. [volume] (Barton, Vt.) 1872-1953, 1922-03-22

u. S. Bureau of Animal Industry.
Before attempting to discuss the
specific points mentioned in the let
ter of Mr.. McInnis, it seems proper
to present a few facts concerning bo-
vine tuberculosis and it's eradication
from a herd or it's exclusion from a
healthy herd.
Any method to be used for these
purposes must involve the detection
of the tubercular animal Such an
animal is one whose body has been
invaded by the tubercle bacillus which
has succeeded in establishing itself
in the tissues, and is growing there
to the injury of the animal. During
the early stages of the disease, the
tubercle bacilli are so enclosed in the
so-called "tubercles", which are an
expression of the reaction of the It's
sues of the animal to the growing
tubercle baeilli, that there is no OPP
portunity for the bacilli to, leave the
body of the affected animal. 1t is, of
course, evident that such an animal
cannot be a source from which other
animals can acquire the disease. Soon
err or later, however, the condition is
so changed that the tubercle bacilli
find opportunity to leave the body
and now the animal in question be-
comes source from which other ami
mails may acquire the disease. 1t is
proper to speak of it as an oppor-
tunity which is presented to the
tubercle bacillus to leave the body of
the animal in which it is growing;
for under natural conditions this or
ganism can grow only in the body of
the living animal. This implies that
unless it has some way by which it
may leave the body of the diseased
animal, and some way by which it
may enter the body of still another
animal, the race of tubercle bacilli
will soon become extinct. Nature has
been as careful to provide ways by
which the tubercle bacillus can main
tain itself, as she has to provide ways
for the perpetuation of plants and
animals. One rmarvels at the means
she uses to fertilize the blossoms of
the flowers, and just as marvellous
ways have been provided for bring
ing disease-producing organisms in
contact with fresh food.
1t will be evident to everyone that
our fight against bovine tuberculosis
will be more successful if we have
some means of detecting the disease
before it reaches the stage in which
the organisms are given off from the
body of the animal than without such
a means; for certainly if the animal
can be detected and removed before
this condition is reached, far less OPP
portunity will be presented for the
tubercle bacillus to find fresh pas
lures in the bodies of the still healthy
animals of the herd. The tuberculin
4<1r.& !, - nj
for detecting the disease before it has
reached the stage in which the bacilli
are leaving the body of the animal
1t is the only weapon which we can
use against this enemy that threatens
our cattle.
1t is idle to say that the test is
weapon by which each shell fired
lands on the mark and explodes.
Some "duds" there will be, but be-
cause there is one dud out of ten
shells, shall we refuse to use shells
in our warfare and stick to solid
shot? The tuberculin test is not
free from error. 1t probably causes
the removal of some healthy animals
from the herds. 1t certainly leaves,
now and then, diseased animals in the
herd; but by it's use thousands of
herds have been freed from tubercu-
losis, and many thousands more have
been protected from this disease. It
certainly gives at least nine successes
to one failure. If we allow the fail
ures to influence US to a greater ex-
tent than the much more numerous
successes, we shall be making a mis-
take. Some who use the test are to
have experiences that will lead them
to believe that they would have been
as well off without it, not better off,
however, while many others will be
certain that it has been great factor
in their success.
In my experience l have not found