Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1909-07-02
CATTLE TICKS AND TEXAS FEVER


CATTLE TICKS AND TEXAS FEVER
How the Disease Can be Stamped Out
and the Quarantine Removed.
The microscopic parasite which
causes the disease known as Texas
fever or tick fever Of cattle is found
in the blood Of affected animals and
is transferred from one to another by
means of the fever tick. A remarkable
feature Of this transaction is that the
disease producing parasites are trans
mitted through the eggs Of the tick
that draws the blood. and not directly
by the old tick. as an engorged tick af-
ter dropping from the host (cow) dies
without ever attaching itself to an
other animal. But its offspring, pro-
duced by the eggs laid after 1t drops
of and before It dies, carry the in
lection and inoculate the first cow
they get on.
The length Of time elapsing between
the exposure Of susceptible cattle to
Infection by ticks and the appearance
of Texas fever among them is depend
ent upon the climate and the develop
ment of the ticks Thus, II northern
cattle are placed on pastures, high
ways, or in pens, cars, etc., In summer
Immediately after the premises have
been infested with ticks from south
ern cattle, Texas fever may occur In
from thirty to- sixty days, as the fe-
male ticks which drop from southern
cattle must lay eggs ana these must
hatch before the northern animal be-
comes infested with ticks and thereby
inoculated with the disease. After the
seed ticks become attached to the AMI
NAL the disease will appear In about
ten days In summer or q somewhat
longer period in winter. In fact, the
disease may occur before the ticks are
large enough to be seen without very
careful search.
One objection that has been advanc-
ed against the fact that the cattle tick
is carrier Of Texas fever is that cat
tie are sometimes found to be suffer-
ing with the disease without showing
the presence Of ticks on their bodies.
This condition In the case Of southern
cattle may be explained by the fact
that the animal already had its blood
infected with the parasites and under
normal conditions was resistant to
Texas fever; however, as q result Of
lowered vitality caused by some other
disease, or by exposure, privation, in
jury, rough handling, ETC., this resist
ance has been reduced and finally
overcome, and the parasites at last
succeed in producing the disease. On
the other hand, when this disease Is
observed In northern animals, the
young seed ticks may be so small and
so few in number as to be unobserved.
Under certain conditions. as when
living on horses, mules, ETC., the ticks
lose their infectiousness, and when
southern cattle not previously infested
with any but these noninfectious ticks
come In contact with infectious ticks
they are just as susceptible as cattle
raised on tick-free pastures.
Many cattle appear perfectly healthy
and yet are infested with ticks and
have the fever parasite in their blood.
Sometimes the owners can not under
stand why such animals should be re-
garded as dangerous to others. and
consider 1t unjust that they should be
subjected to quarantine restrictions.
The fact is that such cattle have usu-
ally contracted the disease In very
mild form at an early age and have
become immune to further attacks, al
though still carrying the parasites In
their blood. They are dangerous be-
cause the fever parasites in their blood
may be transmitted at any time to
susceptible cattle by ticks.
While the disease may be produced
artifically by inoculating a susceptible
animal with the blood Of an infected
one, it is spread naturally only by the
ticks. BY exterminating the ticks,
therefore, the disease can be stamped
out, and the quarantine can then be
The discovery Of the part played by
the tick in the spread Of Texas fever
was made by the bureau of animal in
dustry of the United States department
of agriculture in 1891, and the same
principle has since been found to apply
to the transmission of malaria and
yellow fever from man to man by
and to the spread Of GER
tain other diseases.
Publications containing full infor-
nation about the ticks and giving di-
rections for getting rid Of them may
be obtained free, on application to the
bureau of animal industry, department
Of agriculture, Washington, d. c.