Anthrax outbreaks depend on two factors working together:  the presence of the spores in the soil and suitable weather conditions.  Outbreaks usually ends when cool weather arrives and the bacteria becomes dormant.

Necropsy finding in a carcass inadvertently opened will be: 1) a rapidly decomposing carcass; 2) blood-tinged discharge from natural body openings, 3) incomplete rigor mortis; 4) poorly clotted, dark tarry blood; 5) an enlarged, pulpy spleen, the pulp having a blackberry jam consistency, and 6) septicemic petechial hemorrhages throughout the body.  

Anthrax outbreaks occur occasionally in Nevada usually along the old cattle trails of the early nineteenth century.  Death loss may occur in one pasture, while animals nearby remain healthy.

When anthrax outbreak begins, veterinarians will have the initial cases confirmed through laboratory tests conducted at the Reno Animal Disease & Food Safety Laboratory.  Subsequent cases in an outbreak are to be expected and may be diagnosed clinically, based on disease signs and sudden death loss.  Anthrax is a reportable disease in Nevada .

Because anthrax is often fatal, early treatment and vigorous implementation of a preventive program is essential.  When soil-borne outbreaks occurs, it is best to use antibiotics for the sick animals and to immunize all apparently well animals in the herd and on surrounding premises.

Carcass Disposal

To prevent contaminating the ground with the anthrax spores, the infected carcass must either be burned, (preferred) or deep burial with a layer of quicklime (anhydrous calcium oxide) added before covering with dirt.

Wear long sleeves and protect your hands with gloves, and do not move or open bloated carcasses, as this could release bacteria into the air, causing further disease spread. Do not salvage hides, horns, antlers or any other tissue from the carcasses.

If the animal was housed in a barn, burn the animal's bedding, manure and the surrounding soil. To disinfect panels, trailers or equipment, use an ammonia-based disinfectant, labeled as effective for anthrax. Follow label directions to prevent respiratory irritation!

Other Safety Precautions

Wash your hands thoroughly after handling livestock. Ranchers can contract a skin form of anthrax that requires specific antibiotic treatment.

  See your physician if you develop a sore or lesions after handling vaccine or livestock or burning carcasses.

Keep dogs out of pastures and away from carcasses during an anthrax outbreak. Although dogs are reportedly resistant to anthrax, they can develop infection from the bacteria and may require treatment.

Useful links

CDC - Anthrax

Todar's Online Textbook of Bacteriology - Bacillus anthracis and anthrax