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Badgers and bovine tuberculosis

The problem is two fold:

  1. Since the badger was made a protected species in 1973 the population has been expanding out of control.
  2. A large proportion of badgers, up to 30% in some areas in the SW, Wales and W.Midlands, is endemically infected with bovine TB with some excreting vast numbers of infectious tubercle bacilli into the agricultural environment.

This combination has led to a steep rise in the incidence of TB reactors in cattle, up 18-20% year on year since 1986 (see chart) and spreading in parallel with the expanding badger population.

 

Incidence of TB reactors in cattle

 

Following the Zuckerman report of 1980 culling strategy was compromised due to welfare concerns. In 1997 the Krebs report concluded that the evidence linking badgers to the spread of bovine TB was compelling. But in spite of this culling was abandoned in 1997 and the nine year Randomised Badger Culling Trials embarked upon, since when the disease has escalated out of control.

All the scientific evidence since 1971, when bovine TB was first discovered in badgers and the subsequent culling trials at Thornbury, Steeple Leaze, Hartland point, East Offaly and the Irish Four Counties Trial demonstrated a massive reduction in associated herd breakdowns. Even the seriously flawed Randomised Badger Culling Trials showed a 23% reduction in disease (see ref 2010 below).

Perturbation (induced dispersal of infected badgers) was not a problem in the 5 earlier trials where culling efficiency was in excess of 80%; only in the RBCTs, with the hopelessly inadequate culling rates, was perturbation experienced (see reference 2010 below).

Cattle to cattle transmission is not the major factor in the spread of disease. Several complementary pieces of evidence support this statement since the CVO declared in 1995 that 90% of outbreaks were badger related. It will not have changed since then (see refs 2013 & 2014 below).

Failure to control TB in badgers has inevitably resulted in spill over into other wild and domestic animals including deer, cats, dogs, alpacas and humans. The recent threat to humans from alpacas is of particular concern. Before pasteurisation of milk in the 1950s bovine TB accounted for thousands of human cases of TB.

Vaccination of cattle and badgers is not a realistic or desirable strategy for controlling TB. The scientific basis of the Badger BCG vaccine, currently being widely deployed, which has only a Limited Marketing Authority, is highly questionable. Serious doubts exist about the practicality, effectiveness and safety to badgers of vaccination with BCG in the field (see refs 2010, 2013, 2014b below).

Large numbers of badgers suffer a painful and protracted death from this wretched disease and can take up to 2 years to die. Some 2,000 are estimated to die annually from bovine TB in the south west alone. They constitute the so called super excretors and are the major source of infection for cattle.

 

Emaciated badger carcass: the internal organs were riddled with TB lesions

 

Emaciated badger carcass: the internal organs were riddled with TB lesions

 

See our latest video about Badgers and bovine TB

 

The florid nature of the disease in badgers is quite different from cattle which wall off the infection in fibrous tubercles, which accounts for the low rate of cattle to cattle transmission of the disease (see Gallagher & Clifton Hadley, 2000 below).

Conclusion
The inexorable and unchecked rise in the disease in both cattle and badgers since the late 1990s is a social, animal welfare and agricultural scandal. The disease was almost eradicated in the mid 80s by a combination of TB testing of cattle, slaughter of reactors and culling of badgers.

Killing more and more cattle is clearly not going to control the disease. Strategic culling of infected badgers underground in areas of endemic infection by the most humane method available, targeted by PCR testing is the only realistic strategy for controlling the disease in both badgers and cattle.

The disease is not going to be reduced by the currently available BCG vaccine which is of dubious and unproven efficacy. And doing nothing is not a humane option for either badgers or cattle, which leaves targeted culling of infected badgers as the only proven strategy.

Submissions to Government

  1. A position statement on control of bovine TB, November 2015
  2. Letters to AHVLA questioning the efficacy and safety of the Badger BCG vaccine 2014b
  3. DEFRA consultation on new control measures for cattle - January 2014
  4. DEFRA consultation on strategy for TB free status for England - September 2013.
  5. EFRACom Inquiry on TB vaccination - January 2013
  6. Supplement on vaccination to the DEFRA consultation on TB and badger culling - January 2011.
  7. DEFRA consultation on bovine TB and badger culling - December 2010.
  8. Welsh consultation on bovine TB - December 2010.
  9. DEFRA Consultation on Badger Culling - March 2006

Other statements and reports

  1. Welsh decision to vaccinate badgers letter to Vet Record, April 2012
  2. Shooting badgers - Letter to Vet Record, January 2012
  3. Support for the Welsh CVO letter to Vet Record, April 2008.
  4. Response to EFRACom - April 2008.
  5. Seven point plan by the NFU to tackle bovine TB is to be welcomed - February 2008.
  6. Statement on bovine TB by chief scientist is to be welcomed - October 2007
  7. ISG's depressing final throw on bovine TB - June 2007
  8. VAWM meets with DEFRA TB officials December 2006
  9. Failings of the RBCTs - a letter to the Secretary of State July 2006
  10. Nine point failure of the Randomised Badger Culling Trials July 2006
  11. Cull badgers to halt TB say 350 vets letter to the Secretary of State, February 2005
  12. Badgers must be controlled statement, June 2005
  13. Letter to Vet Record - Bovine TB; the current situation and need, April 2000

Key reference
Tuberculosis in badgers; a review of the disease and its significance for other animals, J.Gallagher and R.S.Clifton-Hadley, Research in Veterinary Science, 2000, 203-217

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