A vet’s pioneering work to break transmission routes of bTB in the heart of badger cull territory appears to have had an unforeseen consequence – a meeting of the minds between vets, farmers and animal activists.
Devon vet Dick Sibley works in what he describes as “the epicentre of bovine TB” with the highest prevalence of the disease anywhere in Europe, and almost one in five farms in the county infected. Efforts to ease the situation through the culling of badgers has stoked passionate reaction – for and against the cull.
Dr Sibley – director of West Ridge Veterinary Practice in Witheridge, Devon, and former president of the BCVA – has been working with a chronically infected herd of 1,100 dairy cattle that have been under restriction and tested every 60 days for the past 7 years.
The problem is the infection is circulating within the herd and maintaining the infection in the population. By employing two, novel bTB tests that are more sensitive than the traditional “skin test”, Dr Sibley has found a significant number of infected animals then become infectious before they are discovered by the old skin test, and pass on the infection to other cows around them.
Dr Sibley said: “Using these novel tests we’ve found what’s called ‘clustering’. We’ve discovered a large number of animals born at the same time and reared together carry the infection through until they are adults, then start shedding and affecting others around them.
“It’s only significant in cattle herds if those infected cattle become infectious, and that’s what we are doing. We’re looking for infected cattle and trying to predict when they will become infectious and removing them from the herd before then, thanks to these more sensitive tests. At the moment, it has been remarkably successful.”
The work on the chronically infected herd at a location that is not being revealed, but which is just outside an official cull area, goes hand in hand with increased biosecurity after tests on badger latrines on the property showed 30% of 273 faecal samples contained detectable Mycobacterium bovis organisms.
A wildlife disease management system has been implemented on the farm with badgers being trapped, vaccinated and released.