Bacterial diseases in animals

Nature

Animal diseases can be caused by unicellular micro-organisms (bacteria), leading to infections and toxaemia. The virulence of bacterial animal diseases depends on the degree of immunity of the host. There are four main types of bacteria: the spherical or coccus form; the rod or bacillus type; the spirally twisted spirillum; and a long filamentous type. The extent of the disease is dependent on the ability of the bacteria to multiply in the host. Transmission may be by contagion, inhalation, infection from food, via insects, or via wounds. Bacterial animal diseases include plague, glanders pseudotuberculosis, enteritis, mastitis, pneumonia, infectious anaemia, anthrax, food poisoning, tuberculosis, Johne's disease, meningitis and haemorrhagic septicaemia.

Background

The global significance of bacterial diseases in animals emerged in the late 19th century, following the pioneering discoveries of Pasteur and Koch, which linked specific bacteria to devastating livestock epidemics. Subsequent outbreaks, such as rinderpest and bovine tuberculosis, underscored the economic and public health impacts of these diseases. International veterinary cooperation and surveillance intensified in the 20th century, as the interconnectedness of animal health, food security, and zoonotic risks became increasingly apparent.

Incidence

Bacterial diseases in animals present a persistent and significant challenge to global agriculture, food security, and public health. Outbreaks such as bovine tuberculosis, brucellosis, and salmonellosis affect livestock and wildlife across continents, leading to substantial economic losses, trade restrictions, and threats to human health through zoonotic transmission. The widespread use of antibiotics in animal husbandry has further complicated control efforts by fostering antimicrobial resistance.
In 2022, an outbreak of lumpy skin disease, caused by a poxvirus but often complicated by secondary bacterial infections, severely impacted cattle populations in India, resulting in the deaths of over 100,000 animals and disrupting local dairy industries.