Indian chieftain. [volume] (Vinita, Indian Territory [Okla.]) 1882-1902, 1891-05-21
TEXAS CATTLE FEVER.
THE DISEASE Attributed TO TICKS
BY THE DEPARTMENT OF AoRI-
CULTURE.

bf THE DEPARTMENT. OF AGRI
CULTURE.
The Conclusion Reached After Extended
Experiments.
A recent dispatch TO the ST. Louis
J Giobe-Democrat says that the depart.
ment Of agriculture has found out what
causes Texas cattle fever This has
long been a mystery. Various theories
have been advanced and combated.
The department has been conducting
experiments for several years, and now
the announcement is made with good
deal OF confidence that the Texas fever
Is due TO & ks. The experiments have
been made by taking different fields.
zone OF these fields says the report,
contained North Carolina cattle with
the ticks: a second, Texas cattle with
ticks; third, North Carolina cattle
without ticks; a fourth, ticks only, and
a fifth, soil from the pastures Of infected
North Carolina farms. Other fields
were also laid out TO test questions
which need not engage our attention in
this brief survey. The results confirm
ed those OF last year. The first animal
TO die was in the tick field containing
no southern cattle. No disease appear
ed in the soil OF the field. Unfortunate
ly, owing 10 the limited space OF ground
at our disposal and its barren, rolling
character, ticks or eggs we're washed
during the heavy rains OF the summer
from the tick field into the field con-
tanning southern cattle without ticks,
although wide lane intervened. The
natives In this field thereupon all died
Of Texas fever. AT the autopsy Of these
cases ticks were found attached % their
skin in abundance. The disease caused
| by Texas cattle could not be distinguish
ed in character from that which was
produced by North Carolina cattle.
These results similarly pointed TO ticks
as the cause. The precise manner in
which they caused the disease WAS by
no means clear, however The theory
which seemed for time most accepta-
BILE was that the adult ticks, as they
dropped of, infected the pastures with
germs which they had taken ia with
the blood OF the southern cattle, and
that the germs were introduced into
the body OF northern cattle with the
food.
"At the same time no parasite could
be detected in the blood OF southern cat
tie examined at various times, on which
fact would lay no more stress, however.
OF more Importance is the popularity
which is exhibited BY this disease in its
period of incubation as it may be proYi-
sioually denominated, and which is OPP
posed TO this theory. Thus. when native
and southern cattle are placed on the
same pasture at the same time il will
take from forty to sixty days for the
disease % appear. After disease has once
shown itself, fresh animals placed in
the same pasture may die, according TO
our experience, within thirteen days
after the beginning OF the exposure.
We might say the virus has to 'ripcn'
on the pasture, which takes nearly two
months, depending on meteorological
conditions. When once 'ripened' this
virus does its deadly work within two
or three weeks. This explanation, how
ever, would be merely formulating our
ignorance concerning the true nature of |
the infectious principle. To the writer
there seemed but one inference to be /
drawn from the facts, and that is that [
the young ticks drop from the southern I
cattle and the eggs laid by them develop |
into Young ticks. After that period |
young ticks are present on the pastures |
until they are destroyed BY the cold or /
the development OF the en- l
bryo in the eggs. In other
words. the period OF incubation OF the I
disease is explained without any diil-
Guilty by the life history Of the tick
The question was solved experimental
ly, in the following manner: Eggs laid
by ticks sent from North Carolina were
placed on dried leaves In a dish partly
tkft - fn h., ]
laboratory until the young emerged
from the egg. The period OF incuba-
tion depends entirely upon the relative
amount of heat, and has varied from
fifteen days in midsummer to forty
days in November when the rooms OF
the labatory became cold at night
These ticks were placed on four differ
ent animals Of different ages, kept
away from any infected Enclosures.
Two were placed in stalls, one OF them
on an adjoining farm, and two were
allowed to stay in patch Of wood land
with healthy cattle. OF these four two
died with Texas fever, as determined
by careful postmortem examination
One OF them was in the stall away from
the station, the other ia the patch OF
woodland. The other two became very
III; one OF them never recovered, but
bad 10 be killed later on; the other re (
covered. In all OF them the germs
we're observed In the blood. The di-
'ease possessed the same characters
lies as those observed in cattle in the
infected pastures during the summer. /
There was an elevation OF temperature
rom nine TO twelve days after the
1oung ticks were placed on the animals,
yOing as far AS l0I fahr in one animal /
Accompanying the fever a gradual re-
luction in the number OF blood corpus
lies was Observed -