We have had several clear TB tests and had become a little complacent so it was a nasty surprise when we went down with TB last year. Although we are in a high TB area, we are a closed herd, with no nose to nose contact with any other cattle and there has never been an outbreak here before. However badgers (along with other wildlife) are known potential carriers of Mycobacterium bovis, the bacterium which causes tuberculosis (TB) in cattle and we have several active badger sets on the farm. Having active sets is not a problem providing all the badgers are healthy, however often when a badger becomes ill (possibly with TB) they are ostracised from their home set, hence they travel onto other territory, and we think this maybe what happened. The cattle are infected via saliva, faeces and urine from an infected animal.
We had an extremely helpful visit from our vet who identified ways in which we could help prevent infection. The most obvious being fencing in the badger sets and latrine areas as it is predominantly in these areas that the TB bacterium will be excreted. It is obviously impossible for us to prevent badgers crossing our land. The vet also suggested thinking about badger vaccination, which we decided to try.
Currently DEFRA are offering funding towards vaccinating badgers against TB. Vaccination of badgers against TB using Bacillus Calmette-Guérin (BCG), the same vaccine given to humans, provides a level of protection and can play a role in limiting TB spread to healthy badger populations. Vaccinating badgers with BCG is proven to significantly reduce infection risk and disease spread in healthy badgers. The vaccine reduces the progression and severity of TB in any vaccinated badgers that do become infected, thus reducing the shedding of the bacterium into the environment.
Once our application was approved we had numerous visits from accredited ‘vaccinators’ who spent time identifying where to place the traps. These traps are locked open and pre-baited with peanuts under a stone slab – this encourages them to dig for the food (their natural behaviour). Once the badgers are used to coming in and out of the traps for the peanuts (typically after 7-10 days), the traps are made active ie the door shuts once the badger is inside. The traps are checked in the early morning and captured badgers are vaccinated with BCG (the same vaccine used in humans),temporarily marked and released. There is no evidence of negative effects on badger health or welfare.
The badgers need vaccinating annually for at least 4 years and ideally in large areas (ie farms next to each other), at the moment there is not a huge uptake nationwide even though there is research showing vaccinations are as effective as culling the badgers in reducing the incidence of TB in cattle. As badger vaccination is carried out in more areas in the UK this will provide an opportunity for the effects on TB in cattle to be better understood.
Six traps were set up around the farm on well used badger areas, of these six only two were ever used by the badgers – and it took over 2 weeks before they were brave enough to take the peanuts. In fact only two badgers were caught and vaccinated this year, but it is a start…..
More information on bovine TB and a range of related topics can be found on www.tbhub.co.uk.