Tuesday, June 26, 2007

More response to the ISG report

We are pleased to post the latest response to the ISG report on badgers and bovine Tb, received from VAWM. (Veterinary Association for Wildlife Management)

In a slick, 7 hour, well orchestrated performance in London on Tuesday, June 19, members of the Independent Scientific Group, chaired by Professor John Bourne, told an audience of vets, scientists, farmers and other interested parties what would be the effect of carrying out a nationwide cull of badgers using the methodology of the Randomised Badger Culling Trials. However what they neglected to say was, in contrast to all previous trials in England and Ireland over the last 3 decades, the culling rates in the proactive zones (recently upgraded as 32-77%) were hopelessly inadequate. And it came as no surprise therefore that only a modest reduction in cattle TB was recorded in the proactive zones and badgers that were missed migrated into surrounding areas to infect more badgers and more cattle. Ten years and £45m later we’ve learnt nothing significant we didn’t know already.

There are a number of reasons why the culling rates were so poor – inadequate number of days trapping per year, wrong time of year, non consent areas of land in the proactive zones, inconsistent farm participation and the method of culling, which allowed significant interference by saboteurs, all of which would have to be overcome in any nationwide culling programme. But although bovine TB may now be the most difficult animal health problem we face in Britain today it has only been made difficult by two decades of neglect. The disease was practically brought under control in the mid 1980s by a systematic programme of testing and slaughtering of cattle reactors and strategic culling of badgers in endemically infected areas. And the badger is probably one of the easiest species of wildlife to cull if done properly, since it lives underground by day in identifiable setts (compare this to the problem in New Zealand, which they have tackled, where the possum is the wildlife reservoir).

Professor Ivan Morrison vividly illustrated how the problem has escalated in England from some 400 cattle reactors slaughtered in 1984 to just over 30,000 in 2005. He also provided evidence that cattle are highly susceptible to TB and may shed infectious tubercle bacilli in the early preclinical phase of the disease. But what he could not say was how significant this may be in the epidemiology of the disease. The ISG believe it to be highly significant but this ignores how effective control measures were up to the mid 1980s and it is worth noting that the CVO in 1995 wrote that 90% of all cattle outbreaks were badger related and less than 10% due to cattle sources. It seems hardly credible that this situation will have changed in the intervening decade.

Professor Morrison also told us what many in the audience already knew that the tuberculin skin test does not pick up all infected animals in a herd. But whilst this may be so it is the tool that has worked in the past. And it may be added it is the test that has been successfully used world wide to eradicate the disease in cattle. Professor Morrison went on to recommend that the gamma interferon test should be developed and used in conjunction with the tuberculin test. But considerable doubt was cast on the benefit that this might bring.

There can be little doubt that the recommendations of the ISG, based on the findings of the RBCTs, are sound. And if such a trial were to be used as the basis of a nationwide cull it could be disastrous. But the recommendation to bear down more and more on the disease in cattle, whilst ignoring the huge reservoir of infection in badgers, defies all logic. It also ignores the chronic welfare problem for the badger.

Professor Bourne’s valedictory hope was that the weighty 290 page report generated by the ISG, now sitting on the Secretary of State’s desk, should “endure”. It is fervently to be hoped that it does not provide the same 10 year excuse for inaction as did the Kreb’s report in 1997.


Any comments direct to VAWM please, and not to the blog.

No comments: