Badgers, cows and bovine TB

Badgers, cows and bovine TB

Bovine Tuberculosis (bTB) is widely pronounced as one of the most important animal health issues of the moment. And with the campaign against the badger cull having gained over 100,000 supporters in a matter of weeks, it is top of the news agenda too. 

Attempts to control bovine Tuberculosis (bTB) are not new. Voluntary testing in 1935 was followed by a compulsory TB eradication scheme (where cattle were compulsory skin-tested and any reacting cattle were slaughtered) launched in 1950. By the ‘70s there were still hotspots of infection in the south-west. Then in 1971 a badger was found with bTB in Gloucestershire – a hotspot area - and badgers became the focus.

Since then a number of badger culling strategies have been tried and many studies have been conducted. And yet bTB is still endemic in these hotspot areas. Why would a new cull be any different? The vast majority of badgers don’t carry the disease (the Randomised Badger Culling Trial showed that an average of just 16.6% of badgers were found to be infected by bTB). Then there is the perturbation effect. In a normally stable badger population, TB infection may be clustered and isn’t spread rapidly amongst social groups but disruption – such as culling – can lead to ‘perturbation’, an abnormal increase in ranging behaviour and a breakdown of territorial boundaries. The effect is more infected badgers, roaming over a wider area, giving an increased risk of disease transmission from badgers to cattle.

In 2007, the Independent Science Group (ISG) concluding their ten year study said that

it cannot conceive of any method of culling badgers, other than complete removal over large areas that would compensate for the perturbation effect.

Even proponents of the cull are only predicting a net improvement of 12- 16 %. And to achieve that, they say they will need to kill at least 70% of badgers. This is why the RSPCA, the Wildlife Trust, the Badger Trust, Sir David Attenborough and others do not back this latest cull. 

Vaccination is the preferred option for many. An injectable badger vaccine is already licensed and a project is underway in a large area in Gloucestershire with the National Trust also funding a project at its Killerton estate in Devon. The badger vaccine is being used by the Welsh Government in an Intensive Action Area in North Pembrokeshire.  An oral vaccine is likely to be easier and cheaper to administer but is a few years away and a cattle vaccine that can be discriminated by screening tests is estimated to also be some years way. (The cattle BCG (like the vaccine we have when we’re teenagers) is currently illegal in the EU and makes screening tests impossible as any vaccinated cattle would have positive results). Improved tests, better biosecurity and movement restrictions all play a part in the battle against bTB. No one denies that action is necessary. With over 18,000 cattle already compulsory slaughtered on farms this year (Defra, Jan-Jun 2012), the need to properly fund the vaccine programme is more urgent than ever*. The welfare of the animals caught up with this disease is our main concern, but bovine TB is also costing millions – to the country, to the tax payer and is distressing to any farmer who may have to lose their herd. 

Bovine Tuberculosis (bTB) is caused by the Mycobacterium bovis.  It is easily transmitted cow-to-cow most commonly through droplets in the breath (rather than ingestion) and is also transmitted cattle-to-badger, badger-to-badger and badger-to-cow. There are some suggestions that around 50% of bTB in cattle may be attributable to badgers even though prevalence in the badger population is low. The bacterium would normally die quite quickly outside a host, but there is evidence of it being able to lie dormant in the soil for up to 11 months in dark and moist conditions and it infects all kinds of mammals including mice, cats, dogs, llamas, pigs as well as cattle and of course badgers.

In 1971, a badger was found in Gloucestershire with bTB. The southwest of England remained a hotspot for TB despite huge strides being made across the rest of the country following the national TB eradication scheme launched in 1950. It involved the compulsory skin testing of cattle and slaughter of ‘reactors’. Focus turned to badgers as a wildlife reservoir of the disease.

Increased testing of cattle in recent years has seen greater numbers of reactor cattle identified and compulsory slaughtered – over 34,000 in 2011, up almost 2,000 from 2010. The percentage of incidences where a farm has lost its TB free status peaked in 2008 and appears to have remained static since 2009 (4.9% Defra GB statistical notice 4 April 2012, table 1).

The TB Eradication Advisory Group and the Animal Health and Welfare Board are taking ideas and comments on solutions to achieve eradication of TB. The deadline is 19 October 2012.

Badgers and their setts are protected under The Protection of Badgers Act 1992.

*£29.9 million had been pumped into research into bTB vaccinations between 1998 and 2010.

The RSPCA's position

On the basis of the current science, welfare concerns and a realistic assessment of what is practical, a widespread cull of badgers is totally unacceptable to the RSPCA.

This position is reflected by the provisions on wild animal control set out in the RSPCA welfare standards for farm animals that must be applied by all Freedom Food scheme members. Under the standards, Freedom Food members are required to apply all reasonable non-lethal and humane methods of wild animal exclusion/control - the RSPCA believes it is unacceptable to use lethal methods of wild animal control as routine practice.

As such Freedom Food would regard it as unacceptable for any of its members to voluntarily take part in a badger cull for the above reasons. To do so would also bring the scheme into disrepute and be a clear breach of the membership agreement, resulting in suspension.

This is not a new position. All members who voluntarily join the Freedom Food scheme, sign up to these standards.

Further reading and sources:

DEFRA - Bovine TB: the disease, its epidemiology and history of its control in England:

DEFRA -  Bovine TB - Key conclusions from the meeting of scientific experts, held at Defra on 4th April 2011

DEFRA: GB National Statistics – released Wednesday 17 September 2012

DEFRA: National Statistics on the incidences of tuberculosis in cattle to December 2011 – 3 April 2012

DEFRA: Bovine TB: The Scientific Evidence.  Independent Science Group, final report, - 2007

DEFRA: annex B - RBCT

DEFRA: Comparing badger control strategies for reducing bTB in Cattle – November 2010

DEFRA: Options for vaccinating cattle against bovine TB – April 2008

DEFRA: Options for the use of badger vaccines for the control of bovine TB – April 2008

  • Published on
    14 December 2012

  • Published in
    News

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