Tuberculosis and Livestock

By William Ogilvie

Tuberculosis, or TB, is a very dangerous bacterial disease that was prevalent in the London during the late 19th and 20th century. The infection caused widespread panic because people did not know all the sources of infection. Further, they also didn’t know they had the disease until symptoms became dramatic and were difficult to treat.

TB typically begins its infection in the lungs, though bodily fluids or aerosol droplets. Pulmonary tuberculosis is the most dangerous form of the infection because it can cause lesions in the lungs, spread the disease into blood and lymph, and ultimately cause lung failure. In many cases, patients don’t report a serious problem until the infection has already spread to a dangerous level since it can look and feel like a minor cold.

Another source of infection was contaminated livestock. Before the 20th century, London had zero restrictions on the buying and selling of livestock from farmers, butchers, and sellers. Animals and livestock were very susceptible to infection with tuberculosis due to their unsanitary living conditions. With no regulations, a farmer could sell an infected animal that would then infect all the meat in the butchers’ facility since the bacteria can still live off dead carcasses. The infected meat could then spread the disease to the public. Outside of human health, diseased cattle caused a major problem for farmers because they were losing large amount of their profit to diseased livestock. However, most people were completely oblivious to TB in animals and it wasn’t until 1882 that the German physician, Robert Koch suggested that infected animals could spread tuberculosis to humans.

Koch discovered the bacteria that caused TB in cattle and human, Mycobacterium bovis and Mycobacterium tuberculosis. The two bacteria, although different, are very similar in nature but spread differently. M. Bovis is the bacteria that infects livestock and animals but does not harm humans. However, M. Bovis can lower the host immune system in humans and allow for infection of M. Tuburculosis. However, even after Koch’s discovery, it wasn’t until the 1920s that London made laws to ban the sale of sick cattle, and not until 1935 that the Ministry of Agriculture and Food launched their first voluntary testing scheme on livestock and meat.

London’s cases of TB rose during the early 20th century, in part due to the lack of governmental regulations on the buying and selling of animal products. TB was everywhere in London. In one borough, Hampstead, there was a total of almost 600 cases of TB from 1912-1921. In 1925, in another borough, there were a total of 1,666 cases of TB registered. Almost every borough of London had close to triple digits in number of cases of TB. It is no surprise to find that the amount of infected livestock had similar numbers throughout those same years. In fact, it got so bad that West Ham officials allowed farmers to get insurance on livestock because they were experiencing so much loss. Livestock insurance soon began to spread to other boroughs. Having insurance allowed farmers to examine their animals and get rid of any that they found to be infected without any loss of profit. Most butchers began only buying animals from farmers who had insurance to protect their own health and meat from infection.

The City of London soon began to pass regulations on livestock buy and sell in hopes to decrease the spread of TB. One of the laws passed was that farmers and butchers were not allowed to sell their meat without a permit that approved the health of the meat. Previously, a piece of meat could go through the entire process without even being looked at by a government official.

Meat infected with tuberculosis. From Handbook of meat inspection (1904).

Over the next 30 years in London, the rates of TB cases reduced drastically. In 1963, there was only a total of 2,259 cases of tuberculosis in all of London, which is thousands lower than what it was in the 1920s. Only a few mores years later in 1967 that a few borough were able to be declared free from TB. A report from Harrow in 1967 stated,

It will be noted that today Tuberculosis is almost non-existent. The eradication of Tuberculosis from the cattle in this country since the war is one of the most spectacular achievements in modern animal husbandry, and it is now six years since evidence of Tuberculosis was diagnosed in a non-reactor on post mortem examination of cattle in a local Slaughterhouse.

Harrow,1967

Routine milk and meat inspection was imperative in Beckenham, London. That is not to say that milk and meat inspection was not conducted in Wandsworth or Bermondsey, but rather Beckenham’s meat and milk inspections were more common due to the

…fifty-nine cases of overcrowding discovered at the 1935/36 survey and the additional twenty-six cases added on December 31, 1938.

Beckenham 1939

In other words, increased TB cases meant  an increase in food supply which possibly meant increased incidences of mycobacterium tuberculosis found in the food.

“The number of carcasses in the Borough in 1939 exceeded those in 1938 by 1,148. Diseased conditions were found in 1,995 carcasses which meant a little over 5 tons of food was destroyed.”

Beckenham 1939

They destroyed all of the diseased carcasses as soon as they discovered them, which showed how thorough they were in preventing TB from spreading further. Similarly this approach was taken for oxen, calves, sheep, pigs, and goats.

The bovines (affected cattle) inspected this year seemed to be healthier than the year before; however there were 21.05% more cows infected with TB.”

Beckenham 1939

On the upside there was “a 25% reduction in TB incidences found in oxen in 1939, as opposed to 63% TB cases in 1938.” Meanwhile, the amount of TB incidences in calves was about 0.32%, which was the lowest incidence case among the types of animals inspected. Furthermore, the number of TB incidences in pigs decreased to 10.6% in 1939.

The regulation and reduction of infected livestock was one of the contributing factors to lowering the number of tuberculosis cases in London during the 20th century. Livestock was one of the leading causes of the spread of the disease and cutting off that supply allowed physicians and medicine to properly do their job. Due to the efforts done in the 1900s, we are now confident in our abilities to reduce the spread of TB and limit the amount of unhealthy livestock.

Sources in MOH

Secondary Sources

Brooks-Pollock, Ellen, and James L. N. Wood. 2015. “Eliminating bovine tuberculosis in cattle and badgers: insight from a dynamic model.” The Royal Society Publishing.

History of TB control in the UK.” Bovine TB Info.

Studies, Division on Earth and Life, and Board on Agriculture and Natural Resources. 1994. Livestock Disease Eradication: Evaluation of the CooperativeState-Federal Bovine Tuberculosis Eradication Program. https://www.nap.edu/read/9144/chapter/3#11