Bovine Tuberculosis is a disease caused by the organism Mycobacterium Bovis, best known for its effect on cattle and humans. Its name comes from the formation of lesions or 'tubercles’, most often in the lungs although other organs can be affected.
It is most easily caught through the respiratory tract, by breathing in
bacilli shed by coughing animals, or through the alimentary tract, such
as by humans drinking infected milk or badgers foraging for insects in
infected cowpats. In cattle, the respiratory tract is the most common
route of infection. In humans drinking infected milk is historically
the most common route, although pasteurisation has largely eliminated
this risk.
Humans can catch the disease, most easily by drinking
contaminated unpasteurised milk. Since the advent of widespread
pasteurisation, only those people working with infected animals are at
risk. Most famously a researcher working at the UK's FERA badger research facility at Woodchester was suspected to have contracted bovine TB in 2009.
While resistant to some common tuberculosis drugs, it is treatable.
In 1971 bovine TB was found to be present in a dead
badger from an infected farm. This was the first time that the presence
of bovine tuberculosis was suspected. Further testing showed that the
disease was present in many wild badgers, leading to the assumption
that badgers were the source of many, if not most, bovine tuberculosis
outbreaks and should therefore be culled to contain the disease.
Since then we have learned that most mammal species are susceptible to
bovine tuberculosis, including rats, foxes, deer, goats, sheep, cats
and dogs.