ANTHRAX HIDES ALONG CATTLE TRAILS
03 Nov 2002
Source: New York Times, October 29, 2001.
Anthrax Hides Along Cattle Trails of the Old West
By ROSS E. MILLOY
UVALDE, Tex., Oct. 26 — Out here in the heart of south Texas cow country, people think about anthrax a little differently than they do in most places in the nation.
"We've had anthrax down here for over a hundred years, and I've been around it all my life," said Randy Hicks, a salesman at the Uvalde Farm and Ranch Supply Company. "I can tell you this much, I'm sure not scared of it."
State officials said more than 1,600 animals died of anthrax in Texas this summer, the most severe outbreak of the disease since 1987. But no people have died. One man in Del Rio contracted cutaneous anthrax while skinning a buffalo in June, the first confirmed case among humans here since 1988. Another Del Rio man is believed to have contracted the disease but recovered before he could be tested, said Dr. Terry Conger, the state's epidemiologist at the Texas Animal Health Commission.
Among Texas ranchers, anthrax is just another occupational hazard among many, like drought, low beef prices or coyotes, that can be managed through care and caution.
"There has been anthrax around for as long as there have been people and animals, all the way back to the Bible," Mr. Conger said. "We've just learned to live with it."
"Most ranchers vaccinate their cattle herds, and that has gone a long way toward eliminating anthrax," he said. "The real problem we have here is among deer in the wild, where there's no accepted method of treatment for prevention yet."
Anthrax in Texas has nothing to do with bioterrorism, local ranchers and state officials say, but stems instead from sources dating to the days of the Old West cattle drives that took free-ranging animals from Texas to markets in the north.
Scattered outbreaks of the disease in Southwest Texas occur on a routine basis, said Julie Rawlings, an epidemiologist with the Texas Department of Health, particularly in Uvalde County and the four counties just north and west of it. The disease recurs here, both she and Mr. Conger said, because of a practice common in cattle drives from just after the Civil War well into the 1890's.
Diseased cattle were simply abandoned along the routes of well-traveled trails like the Goodnight-Loving Trail or the Chisholm Trail, the carcasses left to rot, allowing anthrax spores to migrate into the soil, epidemiologists say.
"If you follow those trails, that's where you'll find anthrax outbreaks even today," Dr. Rawlings said.
Mr. Conger compares anthrax spores left along the old cattle trails to acorns. "The spores have a hard coating, resistant to desiccation, even resistant to some disinfectants," he said. "They literally seed the ground, then migrate back up again in certain weather conditions."
This part of Texas had a rainy spring after a prolonged period of heat and drought, perfect conditions for the anthrax spores to percolate up through the soil, Mr. Conger said. Animals grazing on plant life in contaminated ground ingest the anthrax spores and become sick within 24 hours, he said.
Infected animals will first get a fever, then begin to stagger, tremble and suffer convulsions. Eventually, they ooze blood.
"We've had a wide variety of livestock affected this year, including sheep, cattle, goats, horses, three buffalo and even one llama," Mr. Conger said.
The area's deer population, which has decreased by more than 1,200 animals, has suffered most, Mr. Conger said, and he finds a paradox in that.
"One of the biggest reasons for the emergence of the disease is the popularity among ranchers of leasing out their land for deer hunting," he said. "Large populations of deer lead to overgrazing, so the animals are eating the most infected portions of the plant life close to the ground."
"By encouraging large deer populations, the ranchers are actually creating problems for their other livestock," he said.
That is a reason local ranchers are reluctant to talk about anthrax, said Mr. Hicks, the ranch supply salesman. Ranches that get a reputation for anthrax incidences may have problems when taking their livestock to auctions or markets, he said, and deer hunters may be less willing to lease their properties.
"They don't like to spread it around that they've got anthrax because the ranchers make a lot of money off of deer hunting," Mr. Hicks said. "We're not afraid of it, but we don't talk about it much, either."