11 Sep Camelid testing

An increasing number of vet practices have been called upon to test alpacas or llamas as part of the wider control of bovine TB. Testing in non-bovine animals comes with a whole new collection of complexities and bureaucracy, not least because there is limited legislation governing the ownership of camelid species. These animals do not need to be individually identified by their keepers and their presence close to a herd of cattle is often just a matter of local knowledge. Its very hard for those charged with disease control to ensure that surveillance is complete.

Despite these challenges there has been a significant increase in the numbers of camelid species being TB tested; especially in the highrisk areas of the country. Some individuals have developed a degree of expertise and certain nuances of the procedures involved have started to emerge.

Recently both local APHA staff and a busy vet practice in central England discovered some differences of opinion surrounding how reaction at the injection site, on day two of a skin test, should be described. The choice of words used to describe any reaction became critical in determining whether an animal was determined to be a reactor or not. Discussion arose around a small, but measurable, increase in skin thickness between day one and day two. Due to the very fine skin of the animal the increase was thought to be due to the trauma of the process of intradermal injection and not as a result of any reaction to the presence of the tuberculin.

In such circumstances APHA have confirmed that any, usually small, increased skin measurement should be recorded diligently and noted on the test chart, but the words ‘no reaction’ written in the description box if it is not considered to be either ‘circumscribed’ or ‘some oedema’. For such fine skinned animals this approach can be used when, in the opinion of the attendant vet, there has been no reaction to the presence of the tuberculin.

While it should be noted that this situation is more likely to arise in camelids due to their thinner skin and the fact that measurements are being taken using more precise callipers, it is something that could possibly occur in cattle too, especially in young calves.

All processes for reporting results of TB testing in non-bovine species are still paperbased. Practices are reminded that all paper test submissions should be routed via the XL Farmcare admin team so that there is an opportunity to double check that all paperwork is fully completed. This also allows XL Farmcare to track the progress of all test instructions and to make sure that test instructions where no animals are found to be present, can be closed down quickly without repeatedly hassling the practice team. The WSA must also be submitted on Sam within 5 days of completion on farm so that XL Farmcare can ensure that the Authority will rapidly process payments.