Anthrax kills Wyoming elk and more than 50 cattle for first time in decades

One elk and more than 50 cattle have died of anthrax in south-central Wyoming in the past month, authorities confirmed Wednesday.

Anthrax is found naturally in soil, but has not been documented in Wyoming livestock since the 1970s or in wildlife since 1956. No humans have been infected, according to the Wyoming Department of Health.

Veterinary and wildlife health officials are asking anyone in Carbon County who finds a dead animal, such as an elk, deer, antelope or cattle with no obvious injuries, to leave it alone and call health officials.

“For livestock, the primary concern is the producers located in that region,” said Dr. Hallie Hasel, Wyoming’s state veterinarian. Livestock deaths can represent a “serious economic loss” for ranchers, but Hasel notes that veterinarians can order an effective vaccine that can be administered annually to any livestock in at-risk areas to help stem losses.

Although anthrax hasn’t been documented in Wyoming in more than half a century, outbreaks do occur in livestock in places like Texas, the Dakotas and western Canada, said Dr. Samantha Allen, the state’s wildlife veterinarian. The bacteria can also live in the soil for decades.

Wildlife and livestock officials don’t know exactly why the spore-forming bacteria Bacillus anthracis began killing cattle in the Elk Mountain region, but they said drought followed by heavy rains can sometimes trigger an outbreak.

“While anthrax can be a human health concern at times, we are not concerned at this time that it may pose a risk to the general public in Wyoming,” said Kim Deti, a spokeswoman for the health department. “People can become ill from anthrax if they come into close contact with infected animals or contaminated animal products. Anthrax is not spread from person to person.”

The cattle die

Once infected with anthrax, animals become lethargic, have difficulty breathing and die within a couple of days, although some may succumb within 24 hours. An animal that has died of anthrax typically bleeds from the nose, mouth or anus, does not show rigor mortis and swells rapidly, Allen said.

Cattle began dying of anthrax in the Elk Mountain area about a month ago, Hasel said, and health officials are aware of about 50 to 60 that have died so far on various livestock producers. The Wyoming State Veterinary Laboratory officially diagnosed the cattle with anthrax on Saturday. On Tuesday, the state lab confirmed that an elk found dead in the area also had anthrax.

Livestock and wildlife get the disease by eating near the ground in recently disturbed areas, Allen said. They can also get it by petting a carcass. Carnivores and scavengers such as coyotes or lions are not usually as susceptible to the disease. It has historically been found in livestock in Laramie, Niobrara, Natrona, Carbon, Lincoln, Sublette and Teton counties. The last documented wild animal in Wyoming to die of anthrax was an elk in 1956 in Sublette County.

While anthrax raises fears about the bioterrorist agent sent to postal workers, journalists and government officials shortly after the Sept. 11, 2001, attacks, it is not exactly the same threat, he added. The powder sent in mailed envelopes was a refined version of what lives naturally in soil.

Before the 2001 attacks, people most likely to become infected with anthrax were those who worked with animal skins, hair, bones and wool, according to the health department. Human cases are rare, but health officials continue to urge hunters and ranchers to be cautious.

Health precautions

Anyone hunting in the Elk Mountain area, where large herds of elk range widely along with mule deer and pronghorn, should not shoot an animal that appears sick or touch a dead animal, Allen said.

The Game and Fish Department is not discouraging people from hunting in the Elk Mountain area now that the season is starting, but it instructed anyone in the area not to open an animal carcass “as this can lead to exposure to anthrax spores through the skin or inhalation,” according to a Game and Fish Department fact sheet. People also should not shoot a diseased animal for the same reasons, or allow dogs, horses or other domestic animals to touch a carcass.

Allen also recommends wearing disposable gloves and eye protection, such as sunglasses, when skinning wild animals.

As for the land where the anthrax bacteria lives, Hasel said a change in climate “affects the presence of bacteria in the soil.” Until then, livestock producers are asked to remove cattle from areas such as irrigated hay meadows where cattle have become sick. The bacteria could re-emerge again next year, or years after that, but producers can work with their veterinarians to vaccinate cattle in the area.

Wildlife, livestock and health officials will also host a town hall meeting at 7 p.m. tonight at the Elk Mountain Fire Hall.

The health department has also been working with people in high-exposure areas to provide them with preventative treatment, such as antibiotics and vaccines, Deti said.

“We ask all producers in that region that if they have any acute deaths, do not move them or open them,” Hasel said. “Contact your veterinarian immediately.”