Current Issue #2- Bovine Tuberculosis

One of the most recent issues affecting livestock farmers is Bovine Tuberulosis (bTB), caused by an infection of the Mycobacterium tuberculosis bacteria strain. The disease slowly develops with age as the bacteria responsible for causing bTB only replicates every 12-20 hours. The first noticable sign of infection is in the lymph nodes of the cow with lesions eventually developing on the surface of lungs. This can then progress into a fever, weakness and a lack of appetite with severe cases leading to emaciation.  It is believed to be spread by exchanging respiratory fluids and secretions from infected to uninfected livestock through contact.

Measures have been taken to reduce the spread and number of cases of bTB such as compulsary testing for cattle herds usually every four years and a special slaughter initiative means that clinical signs of bTB are on the decrease. If herds are not tested before a certain date restriction movements are placed on the herd to prevent a potential spread of the disease.

Good husbandry practices on farms also helps to prevent bTB from affecting livestock, these can be just simple measures such as providing good ventilation, ensuring animals are not kept in confined spaces, creating a health plan with the local vet for a herd, keeping wildlife who may carry the disease out of barns and practice good biosecurity to prevent contamination.

However, if bTB is detected in a herd, the case will be referred to the AHVLA, movement restrictions will initially be applied whilst investigations continue. If cattle that are known as "reactors" i.e they have failed two TB tests or given inconclusive results twice, they are considered a potential danger and are isolated, their mik prevented from being used for human consumption and a humane method of slaughter is arranged. Compensation may be awarded to the farmer for any animals that need to be removed for these reasons. In 2004 approximately 22,000 cattle were sent for slaughter due to being infected with bTB.

bTB is additionally a zoonotic disease meaning that it can be transmitted to humans from livestock.
Recently, the government has also been involved in proposals to cull badgers, believed to be carriers of the disease afflicting cattle. However following advice from veterinarians, in Wales the plans of badger culling have been dropped in favour of vaccinations which if conducted should be more cost effective for the government and overall more effective in reducing the spread of the disease. A study of the vaccine was found to reduce TB in badger by at least 74% however whether this will reduce bTB in the long term has not been investigated.

Sources:
http://www.bva.co.uk/atoz/Bovine_Tuberculosis%20.aspx
http://animalhealth.defra.gov.uk/managing-disease/notifiable-disease/bovine-tb/index.htm
http://www.guardian.co.uk/environment/2012/mar/26/badger-cull-bovine-tb-cattle-vaccination
Image: http://news.lancs.ac.uk/Web/News/Pages/Research-shows-parasite-is-hampering-moves-to-cut-cattle-TB-in-UK.aspx