Anthrax

About the Diseases

Nature of disease

It is an acute infectious disease of livestock that occurs throughout the world.
This disease is also known as splenic fever due to the fact that there is extensive enlargement of the spleen (splenomegaly) due to this infection.
Most of the food animals are affected with anthrax.
No mammals have got absolute natural immunity against anthrax.
The most susceptible animals are cattle and sheep.
It is a zoonotic disease.

Causes

The disease is caused by bacteria known as Bacillus anthracis.
When the organisms are exposed to air (oxygen), spores are formed. The spores are never formed so long the organisms remain in the circulation. But when the organisms come out of the body, the spores are formed.
The spores are very much resistant to cold, hot, chemicals and drying.
The spores may remain viable in the soil for a considerable period of time and for ten years in the infected tissues and cultures.
The soil can maintain the organisms in spore stage for years together without endangering the life of animals.
The spores remain resistant to 100˙C for 5 minutes. But it will be destroyed at 100˙C for 10 minutes.
The vegetative form of the bacteria can be killed at 60˙C for 30 minutes. In autoclave at 120˙C for 15 minutes all the vegetative forms can be killed.
Commonly available chemicals cannot kill the spores.
5% NaOH can effectively destroy the spore contaminated objects.

Mode of Transmission
The anthrax spores have got the ability to remain viable in the soil for a considerable period of time and thus remain as a continuous source of spread to the susceptible animals. The stream, rivers and flood may carry the spores from place to other and thus may spread the disease to the virgin soil. Carnivore animals may carry the infection to the distant places. Carnivores may contact the infection through ingestion of contaminated carcases. Flying birds may disseminate the infection from one place to the other. Various flies have been implicated as carrier of infection during the fly breeding seasons. Animals while graze in the infected pasture pick up the infection through ingestion or through breach in the oral mucosa or skin. The new area may be infected due to contaminated animal products such as bone meal, fertilizers, hide, hair, wool, grain or forage.

Symptoms

Clinical symptoms
There is elevation of body temperature (104 to 108˙C). Animal refuses to eat and there is development of bloat. Animal is extremely depressed. Animal shows distressed breathing. Extreme dyspnoea leads to mouth breathing due to oxygen hunger. Sudden death within 48 hrs of illness of animal Following death there is oozing of blood from the natural orifices. Oedema may predominantly notice under the neck, brisket region, thorax, abdomen and flank. In per- acute form animals may be found dead without any premonitory signs.

Management Methods

Preventive measures

Periodical and regular vaccination should be done.
Strict quarantine measures in anthrax prone areas.
Preventing the introduction of infected animals into disease free areas.
Carcasses should not be opened as it may contaminate the pasture.
Care should be taken to destroy the dead body by deep burial with quick lime.
Persons handling the anthrax infected animals should adopt adequate sanitary measures.
The adjacent areas of the dead and infected animals should be thoroughly disinfected by 3% per acetic acid or 10% caustic soda or 10% formaline.
The fodder from infected pasture should be destroyed and not to be given to the other animals.

	Suggested first aid
The dead animal body should not be opened. Should have consultation with nearest qualified veterinary doctor. This disease should be brought under the notice of the regulatory officials in case of an outbreak. Care should be taken to destroy the dead body by deep burial with quick lime.

Zoonotic importance
Anthrax is a zoonotic disease and thus has public health significance. Anthrax bacilli or spore may produce cutaneous abscess known as “hide porter’s disease”; pneumonia known as “wool sorter’s disease” or dysentery in man. Animal clinicians should take care while making blood smear from dead animals. Persons handling the anthrax infected animals should adopt adequate sanitary measures for their own safety.