There is currently no sensitive and reliable diagnostic test for bovine TB in live badgers in the field. Bovine TB is most reliably detected by post mortem examination or by the less sensitive method of taking clinical samples (for example, blood, urine, tracheal swabs and faeces) from anaesthetised live badgers. Tissue samples are then confirmed by culture of Mycobacterium bovis (M. bovis ) in the laboratory. However, M. bovis grows very slowly so culture results can take six weeks to several months to come through. Various blood tests can be used to measure the immune response to bovine TB, one of which takes about 30 minutes, and has about 80 per cent. sensitivity in detecting severely infected animals.
The drawback of these tests for live badgers is the need to anaesthetise the badger in order to sample it, hence they are suitable for research purposes only.