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The
first case of what we know today as Texas cattle fever occurred in
Pennsylvania in 1796, when southern cattle introduced to that state
died from the disease.
Texas fever made its name during the cattle
drives of the 1850s when Texas cattle on their way to market spread
the disease to northern states. The Texas cattle, mostly longhorns,
escaped suspicion at first because they were tough and rangy and immune
from the disease. But they dropped the ticks that cause the disease
along the trail, causing cattle from other states to drop like flies.
Why the longhorns, mostly from South Texas, didn't get the fever puzzled
cattlemen and veterinarians for decades. They theorized that the longhorns
loaded up on poisonous plants that, for whatever reason, didn't harm
them but made their waste so toxic that even a tiny amount of it accidentally
ingested by another cow could kill it.
Modern research found that the calves are born with a partial resistance
to the infection that goes away gradually as the calf matures into
a cow. The calves supposedly suffer a mild attack at an early age
and develop enough immunity to keep from getting sick but not enough
to get rid of the pathogen. They stay healthy enough to make it to
the dinner plate but remain carriers of the disease.
Drawing on the work of pioneering bacteriologists Robert Koch of Germany
and Louis Pasteur of France, American scientists Theobald Smith and
Fred Lucius Kilborne of the federal Bureau of Animal Husbandry discovered
that ticks cause the disease by sucking blood from the animal and
then dropping into the grass to lay eggs. The young ticks come into
the world already armed with the protozoa that causes the disease;
they're a dead cow waiting to happen.
All that ranchers and citizens in other states knew about Texas fever
during the cattle drive era was that it came from Texas, which made
the state's cattle bovine non grata along the old cattle trails.
States passed quarantine laws routing cattle away from settled areas
and restricting passage of herds until the winter months when it was
too cold for the ticks. Sometimes firearms were involved.
Not all Texas cattle were immune from the disease. Panhandle cattle
were especially susceptible, leading pioneer Panhandle
rancher Charles
Goodnight to impose his own "Winchester quarantine" on cattle
coming into the area from South Texas. Armed ranch hands directed
the drovers to a specific trail or they held the cattle until winter
when the threat diminished. Either way, the cattle didn't cross Goodnight's
ranch.
Goodnight's
actions mattered not at all to people in other states when Goodnight
trailed his own Texas cattle north. Once, in Colorado, a group of
15 to 20 armed men met Goodnight, his crew and cattle at a river crossing
and told him to stop his cattle drive right there. Goodnight was a
man of a few well-chosen and sometimes profane words. Armed with a
shotgun and backed by several men with loaded Winchesters, Goodnight
rode up to the men and told them point blank, "I've monkeyed as long
as I want with you sons-of-bitches." And he continued on his not-so-merry
way.
Texas
fever, along with the construction of railroads, helped put an end
to the cattle drives, but the disease persisted as a major problem
for the state's cattle industry. Elaborate federal quarantine laws
segregated southern cattle in railway cars and stockyards. Mark Francis,
the first dean of the Texas A&M School of Veterinary Medicine, developed
a method of immunizing cattle shipped to Texas from northern climes
by injecting them with small amounts of blood from infected animals,
earning Francis the unofficial title of "Father of the Texas Cattle
Industry."
The Livestock Sanitary Commission (now the Texas Animal Health Commission)
was established in 1893 specifically to deal with the disease. Robert
J. Kleberg with the King Ranch invented, built and used the first
cattle-dipping vats that he filled with a pesticide solution, a method
still in use today. The USDA declared King Ranch tick free in 1928.
By 1943, the disease was eradicated in this country, except for a
500-mile stretch along the Texas-Mexico border. Donald Thomas, Ph.D.,
of the Cattle Fever Tick Research Lab near Edinburg, recently told
the journal Entomology Today that the ticks have become "immune
to just about every class of pesticides on the market." And so the
battle continues, though on a much smaller scale. At least for the
time being. |
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