Staunton spectator and vindicator. [volume] (Staunton, Va.) 1896-1916, 1909-07-09
How Cattle Ticks
Spreads Texas Fever.

HUN Uulllu llUhD.
Spreads Texas Fever.
BY Exterm1nating the Ticks the
Disease can be Stamped Out and
the Quarantine Removed.
The microscopic parasite which
causes the disease known as Texas fe-
yer 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 remarka-
BILE feature of this transaction is that
the disease producing parasites are
transmitted through the eggs OF the
tick that draws the blood and not
directly by the old tick, as an engorg-
ed tick after dropping from the host
(cow) dies without ever attaching it
self to another animal But its off
spring, produced by the eggs laid after
it drops off and before it dies, carry the
infection 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 devel-
opment of the ticks. Thus, if North
ern cattle are placed on pastures, high
ways, or in pens, cars, ETC., in summer
Immediately after the premises have
been infested with ticks from Southern
cattle, Texas fever may occur in from
30 to 20 days, as the female tick which
drops from Southern cattle must lay
eggs and these must hatch before the
Northern animal becomes infested
with ticks and thereby inoculated with
the disease. After the seed ticks be-
come attached to the animal the dis
ease will appear in about 10 days in
summer or somewhat longer period
in winter. In fact, the disease may
occur before the ticks are large enough
to be seen without a very careful
search.
One objection that has been advanc-
ed against the fact that the cattle tick
is carrier of Texas fever is that cattle
are sometimes found to be suffering
with the disease without showing the
presence of ticks on their bodies. This
condition in the case of Southern cat
tie may be explained by the fact that
the animal already had its blood af-
fected with the parasites Bnd under
normal conditions was resistant to
Texas fever; however, as a result of
lowered vitality caused by some other
diseases, or by exposure, privation, in
jury, rough handling, etc, this resist
ance has been reduced and finally
overcome, and the parasites at last sue
ceed in producing the disease. On the
other hand, when this disease is OBJ
served 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
Southerd cattle not previously infected
with any but these non-infectious 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 affected 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 a 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 sus-
ceptible cattle by. ticks.
While the disease may be produced
artifically by inoculating suscepti-
ible animal with the blood of an in
fected one, it is spread naturally only
by the ticks, By exterminating the
ticks, therefore, the disease can can
be stamped out, and the quarantine
can then be removed.
The discovery of the part played by
the tick in the spread of Texas fever
was made by the Bureau of Animal
Industry of the United States Depart
ment of Agriculture 1891, and the same
principle has since been found to apply
to the transmission of malaria and
yellow fever from man to man by mos
quitoes, and to the spread of certain
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, Depart
ment of Agriculture, Washington,
D. G..
Life 100, 900 Years Ago.