What’s Behind Animal Deaths In Texas’ ‘Anthrax Triangle?’

Anthrax is rarely found in Texas wildlife and livestock. But a particular corner in Southwest Texas, between Ozona, Uvalde and Eagle Pass, has become known as the “anthrax triangle.” An alarming 14 cases of the disease, caused by a deadly bacterial spore, have been reported to the Texas Animal Health Commission this summer. Martin Hugh-Jones, professor emeritus and veterinary epidemiologist at Louisiana State University, says a mix of bad ranching practices and a special climate have resulted in the recent anthrax outbreak. In the mid-20th century, the bones of anthrax-infected animals that had died on the East coast were used to make an organic fertilizer for plants and a nutritional supplement for animals. The bone meal was sold to Texas ranchers, and eventually ended up on salt licks or mineral blocks used for livestock and wildlife nutrition, Hugh-Jones says. Alkaline soil, also known as “sweet soil” for its high pH and calcium levels, mixed with humus, a component of soil made of decomposed plant life, was a good environment for anthrax spores. “What you have this year is what we call a Texas paradigm – you have late spring, early summer, heavy rain, and this encourages the hatching of the biting flies,” Hugh-Jones says. Biting female flies spread the spores as they feed on sick or live animals, Hugh-Jones says. Livestock are vaccinated for anthrax every spring by ranchers. The vaccine is very effective, and comes at a low cost – about $.40 cents a dose, Hugh-Jones says. However, anthrax can still affect wild animals that are difficult to vaccinate in large numbers, like white-tail deer. He says there aren’t yet methods of immunizing wild animals, by adding vaccines at feeding stations, for example...MORE