There are hopes that a new test may soon be developed to detect bovine tuberculosis (bTB) in camelids.
There are hopes that a new test may soon be developed to detect bovine tuberculosis (bTB) in camelids. Camelids (alpacas and llamas) can catch bTB, but do not readily display symptoms when they are unwell. At present, the cattle skin test is the only official test that can be used, but alpacas and llamas have a low response to this. There is, therefore, an urgent need for a reliable test. The British Alpaca Society (www.bas-uk.com) is currently funding research into the development of a gamma interferon blood test. Separately, the TB Support and Research group (www.alpacatb.com) has commissioned a project to investigate whether polymerase chain reaction (PCR) could provide a more rapid and reliable test. PCR is a method of rapidly duplicating DNA to provide large enough samples for investigation. This work is being carried out by the Animal Health Veterinary Laboratories Agency. Claire Waring, BAS secretary, said: “If PCR proves to be sufficiently sensitive and specific, there is a chance it could be used for diagnosis in live animals, which would be a great step forward in our fight against this disease.” Mike Birch, an alpaca breeder and former BAS chairman, said: “PCR is currently used by AHVLA for a number of other diseases, for example Johnes disease. AHVLA microbioligists are hopeful that, due to the advanced level of bTB often found in camelids, it may be possible to detect m.bovis in faeces, nasal swabs or blood. “The study is under way and the results are eagerly awaited, not just by camelid owners, but also by the cattle community, who have shown their support by contributing to the cost of the research,” said Mr Birch. “If it proves successful, PCR may be able to be used as a test for herds not under restrictions where an animal shows clinical signs of possible bTB, as a test to remove infected animals from herds where bTB has been confirmed, or whilst culture results are awaited. Speeding up the time taken to confirm that visible lesions are, in fact, due to bTB alone would be hugely valuable in both camelids and cattle – confirmation by culture can take 12 weeks.” Bovine TB is a disease that can affect all animals, both domesticated and wild. There are a number of spill-over species that are increasingly being found to have bTB, including goats, sheep and pigs.