Review of anthrax: A disease of farm animals

Abstract

Anthrax is a rapidly fatal infectious disease affecting herbivores and people. In the farm animals, cattle and sheep are more susceptible, followed by goats and horses, while dwarf pigs and Algerian sheep are relatively resistant. Bacillus anthracis, the causative agent of anthrax, produces spores and persists for decades in the soil, initiating an outbreak through a favorable climate shift. Anthrax is enzootic in many Asian and African countries, and is reported in Australia, some parts of Europe, and America. The clinical courses of this disease in animals are peracute, acute, subacute, and chronic forms. In severely infected cases, the animals are dead without premonitory clinical signs. The blood may fail to clot and can be found in the mouth, nostrils, and anus in the animals that die from anthrax. This bacterium is susceptible to many antibiotics, yet only penicillin and oxytetracycline have the most effective under field conditions. When an outbreak occurs in a defined area, it is necessary to take early steps to break the infection cycle by maintaining strict biosecurity and vaccinating uninfected animals. This disease is still a challenge to farm animal production in many countries. This review intends to give a fair knowledge of the etiology, epidemiology, pathogenesis, clinical presentation, diagnosis, treatment, and control of this disease.

Keywords: Anthrax; disease; farm animals; review.

Figure 1.. The transmission cycle of anthrax.

Figure 2.. Staining and immunological techniques are used for the diagnosis of anthrax. (a) M’Fadyean staining, (b) FAT using monoclonal antibodies for cell wall, (c) and capsule were useful for the detection and identification of anthrax bacilli. In advanced decomposition, detection of the bacteria in the carcass is almost impossible where a precipitation test (Ascoli’s thermo precipitation test) is suitable for diagnosing anthrax (d). Black and white arrowheads indicate the bacteria after staining. Figures a–d were taken from or kindly provided by Anne Boyer (Anthrax Toxin Team Leader, CDC), De et al. [69], and Microbe Notes [83], respectively.