NEWS for North Dakotans
Agriculture Communication, North Dakota State
University
7 Morrill Hall, Fargo, ND 58105-5665
May 28, 1998
A cow that died mysteriously recently in southeastern North Dakota died of an anthrax infection, according to pathologists at North Dakota State University’s Veterinary Diagnostic Laboratory.
"That’s a reminder that anthrax is something we have to live with and deal with," says Charlie Stoltenow, veterinarian with the NDSU Extension Service. "Being aware of unexplained livestock deaths and sudden changes in livestock health go a long way toward preventing the spread of anthrax and other diseases."
Close monitoring of livestock will help identify disease problems early. And a veterinarian should be called to diagnose any unexplained livestock deaths, Stoltenow says.
The farm where the anthrax-infected cow came from will be quarantined for at least a month. All other livestock on the farm will be vaccinated for anthrax.
Typically, there are only one or two cases of anthrax in North Dakota each year.
Anthrax is a generalized bacterial infection that attacks internal organs of animals. The bacteria produce toxins that kill victims by kidney failure or shock. It only takes a few days for the disease to kill its host.
Stoltenow explains that anthrax bacteria reproduce by forming spores. Those spores can live for 100 years or more in the soil until a warm-blooded animal ingests those spores. The spores are very resistant to sunlight and drying, he notes.
"The spores reside only in certain areas and only in certain soil types. We’re not sure what activates the spores, but it does seem that certain climate changes, especially floods, seem to activate those spores," Stoltenow says. "It’s surprising that we didn’t see any anthrax last year."
Research indicates that livestock may ingest spores while they’re grazing very short grass. That’s a condition which exists when forage is in short supply. Under those conditions, the cattle may also eat plants that are more coarse and tougher than normal. That plant material may inflict wounds inside their mouths, further opening the livestock to infection by anthrax.
"Once the spores are in the system, the bacteria proliferate and it’s only a matter of days until the animal is dead," Stoltenow says. Anthrax isn’t usually spread from animal to animal, but dogs and coyotes that feed on carcasses can become infected, and an increased number of spores from a dead animal can increase the risk of infection for other animals in the area.
Anthrax is infamous because it can kill humans and has recently gained notoriety for its potential use in biological warfare. Stoltenow says it’s unlikely that the infection will be spread naturally from livestock to humans.
"As long as the carcass remains intact and is burned or buried properly, the bacteria will remain in the carcass and there’s little danger of spreading the disease," he says. That’s why veterinarians are advised not to perform post mortem examinations on suspected anthrax cases. Instead, small blood samples are drawn and cultured to determine if anthrax is present.
Carcasses that might carry anthrax should be covered with lime and buried. Carcasses can also be burned, but the fire must be extremely hot so the carcass is consumed rapidly. "We’re essentially talking about an cremation," Stoltenow says.
###
Source: Charlie Stoltenow (701) 231-7522
Editor: Tom Jirik (701) 231-9629