North Dakota agriculture commission Doug Goehring announced Aug. 12 that “anthrax has been confirmed in a group of cows in a pasture in east Billings County” in North Dakota, marking the state's first reported case of the disease this year.
Goehring said the case is a reminder to livestock producers to take action to protect their animals from the disease, especially in areas with a past history of the disease. The case, in western North Dakota, was confirmed Aug. 9 by the North Dakota State University Veterinary Diagnostic Laboratory based on blood and tissue samples submitted by a veterinarian with Cross County Veterinary Service in Dickinson, N.D.
“Producers in past known affected areas and counties should consult with their veterinarians to make sure the vaccination schedule for their animals is current,” North Dakota state veterinarian Dr. Susan Keller said. “Producers in Billings County and surrounding areas should confer with their veterinarians to determine if initiating first-time vaccinations against anthrax is warranted for their cattle at this time.”
Effective anthrax vaccines are readily available, but it takes about a week for immunity to be established, and the vaccine must be administered annually for continued protection, Keller said. Producers should monitor their herds for unexplained deaths and report it to their veterinarians.
According to the North Dakota Department of Agriculture, anthrax has been reported most frequently in northeast, southeast and south-central North Dakota, but it has been found in almost every part of the state.
“Scattered, heavy rain in that area may have contributed to the disease occurrence in that pasture,” Keller said.
A few anthrax cases are reported in North Dakota almost every year. However, in 2005, more than 500 confirmed deaths from anthrax were reported, with total losses estimated at more than 1,000 head. The animals affected included cattle, bison, horses, sheep, llamas and farmed deer and elk.
No cases of anthrax were reported in North Dakota in 2016, one case was reported in 2017 and none were reported in 2018.
Anthrax is caused by the bacteria Bacillus anthracis. The bacterial spores can lie dormant in the ground for decades and become active under ideal conditions, such as heavy rainfall, flooding and drought. Animals are exposed to the disease when they graze or consume forage or water contaminated with the spores. Biting insect control is also advised in affected pastures and neighboring areas.
Anthrax continues to be a growing concern in Texas, especially through the “anthrax triangle” region, according to Texas A&M AgriLife Extension Service sheep and goat specialist Dr. Reid Redden.
The Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) has now confirmed 18 positive cases of anthrax in animals, the Texas Animal Health Commission announced in its fifth situational update report. The first case was confirmed June 21, and the most recent case was confirmed Aug. 6.
In an average year, TVMDL diagnoses two to three cases. However, this year’s wet winter, followed by a dry, warm summer, created ideal conditions for the bacteria to emerge, Redden said.
“I’ve spoken to ranchers in the affected regions who have had animals die of anthrax or who have animals exhibiting the signs and symptoms of the disease,” Redden said. “However, we don’t want people to panic. This disease is fairly well confined to a region in southwest Texas, and animals can be protected in advance by being vaccinated.”
Animals typically contract the disease through eating contaminated soil or inhaling spores. Once an animal is infected, the disease can be spread through their bodily fluids, hide and meat, and caution should be taken, Texas AgriLife Extension said.
Biting insects may also spread the disease. Horse flies are experiencing high populations this year and are known vectors of the disease, but the extent of their role in spreading anthrax is unknown, the announcement noted.
In Texas, the “anthrax triangle” is the area where cases are traditionally seen. So far this year, cases have been found in Crockett, Kinney, Sutton, Uvalde and Val Verde counties in Texas, and the species infected include goats, deer, cattle, antelope and horses.
“We tend to see anthrax when the hot part of the summer starts, and then it tends to go away once it gets cooler, but cooler weather could still be a couple of months away,” Redden said. “This problem could get a lot worse before it gets better.”