Anthrax case confirmed in Sioux County, ND

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BISMARCK, N.D. — North Dakota has had its first confirmed case of anthrax this year in Sioux County, where eight head of cattle died out of a herd of about 200.

State Veterinarian Susan Keller says the surviving portion of the herd has been vaccinated, and the cattle are now under quarantine as required by state law. The case was confirmed Sept. 21 by the North Dakota State University Veterinary Diagnostic Laboratory based on samples submitted by a veterinarian with the Mandan Veterinary Clinic.

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.

Keller says any disturbance of the soil, which can come from times of drought followed by heavy rain or from human activity like fixing fences after a blizzard, can stir up spores.

In 2005, there were 109 anthrax cases that led to more than 500 confirmed livestock deaths and possible loss of more than 1,000 head of livestock including cattle, bison, horses, sheep, llamas and farmed deer and elk, mostly in eastern North Dakota, Keller says overland flooding may have been to blame.

Anthrax has been most frequently reported in northeast, southeast and south central North Dakota, but it has been found in almost every part of the state. Cases of anthrax are common in most years. Two cases were confirmed in 2015 but none were confirmed last year.

One case of anthrax also has been reported in 2017 in South Dakota, in Pennington County.

Since not every death loss in a pasture is investigated, Keller says there may be more anthrax cases than officials know of. However, any time there is unexpected death loss, a veterinarian should be consulted, she says.

By the time it is clinically apparent, anthrax is always fatal in cattle, Keller says. Effective anthrax vaccines are readily available, but it takes about a week for immunity to be established, and it must be administered annually for continued protection.

Kyle Gustin, manager of Stockmen's Supply in Mandan, N.D., says a dose of anthrax vaccine costs about 78 cents. The amount of the vaccine sold stays pretty consistent from year to year and doesn't tend to spike in years with conditions that lend themselves to increases in anthrax cases.

Keller says the vaccine is very effective. In 2005, when there were 109 cases of anthrax in North Dakota, mostly in eastern North Dakota, death loss stopped very soon after vaccination.

There are many diseases that producers need to manage along with potential anthrax problems, and Keller recommends producers work with their veterinarians to determine whether they need to vaccinate for anthrax and other diseases. Ranchers in Sioux County, as well as the nearby counties of Morton, Grant and Emmons, in particular, should talk to their veterinarians soon, she advises.

Keller explains the anthrax that infects cattle in pastures is called "vegetative" or "wet" anthrax and is not the same form as the anthrax that is considered a bioterrorism threat. However, people should be sure to wear gloves any time they are dealing with animals that died, she says.

Ranchers also need to be sure they're working with a veterinarian to make sure they are properly disposing of carcasses, as proper carcass disposal can reduce incidence of spread.

An anthrax factsheet is available on the North Dakota Department of Agriculture website at www.nd.gov/ndda/disease/anthrax.