Anthrax Pathology

The nature, cause, origin, and progress of anthrax.

Anthrax, a disease of mammals and humans, is caused by a spore-forming bacterium called Bacillus anthracis. The presence of the disease depends on two factors working together:

• the presence of anthrax spores in the soil, and
• suitable weather conditions

The bacteria grow and contaminate the surface soil and grass after periods of wet, cool weather, followed by several weeks of hot, dry conditions. Outbreaks in animals usually end when cool weather arrives and the bacteria become dormant.

Anthrax has an almost worldwide distribution and is a zoonotic disease, meaning it may spread from animals to humans. All mammals appear to be susceptible to anthrax to some degree, but ruminants such as cattle, sheep, and goats are the most susceptible and commonly affected, followed by horses, and then swine.