3 Nov 2012, 3:48 PM
There are an increasing number of alpacas being dragged into the system, many are pets. The owners are coerced into having them tested using the skin and blood tests that seem to be even more imperfect for this species than they are for cattle. Many alpacas are being slaughtered after testing positive to the badger Brock TB stat pak. There are no alterations to this test assay other than camelid blood. They are then found to have absolutely no sign of bTB, either at post-mortem or following tissue culture.
Many alpacas are kept as well loved pets and the owners are not even being properly compensated. Alpaca prices have remained constant for years now and they are not in the food chain but kept and breed for fine fleece. Owners are only being paid £750 for each alpaca killed which will not even pay for a good stud fee.
One alpaca owner approached us and we agreed to do a case study based on her experiences to date with the bTB policy. She told us that many alpaca owners do not want their animals testing and with the dismal results and experiences of those who are now embroiled in testing, one can hardly blame them. The owner (AD) the subject of this case study has clearly been through hell and the sorry saga seems to have no end. All of us who have been through similar experiences can sympathise with what she is going through. My daughter is so upset and destroying some of our older pets traumatizes us and most upsetting of all destroying young two and three year olds who, as my daughter put it ‘have not had a life yet’. It is dreadful, my school is supportive of my efforts and the science department where I work horrified at how unscientific and how wrong this is!”
Clearly the Government do not really understand just how their wretched policy is ruining the lives of many decent people.
AD keeps a small herd of around 20 alpacas for fleece. Her family spin the fleece to make fine garments. The herd are also like pets to the whole family, each has an individual character and some mean as much to the family as their dogs. She was forced to slaughter five of her alpacas after Animal Health used a new combined skin test and blood test on them. The single bovine only skin test was followed by the Brock TB stat pak blood test 14 days later. They all passed the single bovine only skin test but five out of the seven tested failed the stat pak blood test. Only the pregnant, old or young failed. On postmortem there were no visual lesions (NVL) in any of the animals slaughtered because they failed the tests. She does not believe any of her animals had bTB and according to normal research standards they would be classified as false positives. All the herd have undergone the comparative skin test and all passed.
There are approximately 30,000 alpacas (www.bas-uk.com) and around 2000-4000 llamas (www.britishllamasociety.org) currently registered in Great Britain. There are also non-registered animals but the numbers of these are unknown. Camelids are seen as exotic species, so they do not currently come under the general livestock regulations. In England they do not need to be tagged or regularly bTB tested. They are not subject to movement controls either. In Wales there are stricter rules and camelid keepers do have to keep movement records under the Tuberculosis (Wales) Order 2011 (www.wales.gov.uk/bovinetb). However, we understand that most BAS members keep a herd book on their premises recording all movements and there is an electronic herd book recording all registered alpacas.
Ante mortem TB testing of SAC usually takes place only for export certification purposes and in response to TB breakdowns that are confirmed by positive culture of M. bovis. bTB testing is voluntary and owners cannot currently be forced to have their animals tested.
AD agreed to get her animals tested following a massive bTB herd breakdown on an alpaca farm in West Sussex when around 470 alpacas were culled in Spring 2012 after testing positive for bTB. She believed she was being responsible and trying to stop the spread of disease. At first Animal Health claimed that the tests had been validated and AHVLA staff, including Simon Hall (the chief vet), Anthony Greenleaves (the Regional Director), Ian Greenwood (senior staff) and Edwina Thirkell (the Director of England) kept sending links to the BAS funded research on ante mortem tests in camelids. It took 3 months for AHVLA to admit that they had not researched the effect of a skin test on the stat pak serological test. It was worrying to realize then that they did not even read the research papers they used to back up their testing policy.
The test listed in the BAS report is not even clear. It is listed as the ‘Chembio vet tb stat pak’ but two Chembio stat paks that might be the test used exist on the Chembio website, ie the Chembio camelid vet tb stat pak (which has been removed from the site since AD made them aware of the high false positives) and the Chembio Brock TB stat pak for badgers. AD says, “I have a copy sent to me from AHVLA of the Standard Operating Procedure for the test used on my animals and it is the Brock TB Stat Pak from Chembio. They say they follow these tests completely to the letter but one key problem is the fact that no-where in the SOP is camelid blood mentioned!”
AD told us, “The problem with the combined test is that the only animal it has been routinely used on is cattle and the only blood test used with the comparative skin test is the gamma interferon test, which has been used at day 3, whereas the stat pak is taken at days 10-30. The results on camelids have proven, so far, to be very unreliable and the stat pak seriological test has not produced evidence that the data in the research studies on the blood test alone it is reproducible”.
Shelley Rhodes, one of the researchers of the BAS report stated in an email to AD that ‘The single intradermal (PPDB) skin test will increase sensitivity because it will detect responses to all mycobacterial products including of course bovine TB (M. bovis) products, whereas the comparative test will discount those responses to environmental mycobacterial products (represented by PPDA).’
Defra is still claiming that the single bovine only skin test will increase sensitivity but will not affect the specificity, but this is in total contradiction to what Shelley Rhodes is saying.
AD Says, “If you inject any animal with tuberculin it will cause antibodies to be produced. If this is measured later in an animal with a weakened immune system (eg pregnant, old or very young animals) they can fail the test. In fact with an animal not encountering TB before you would expect a slow and steady rise of antibodies to be produced and they would reach a peak later. So far 91 alpacas (owned by several different owners) have been slaughtered and not one has had any sign of bTB. We felt that we wanted validated blood test combinations and not the skin test. Chembio states that multiple skin tests could lead to false positives and it is worth bearing in mind that research shows that in cattle that have recently given birth they can fail the blood tests and those with another disease that makes the immune system weaker”.
Interestingly on the 28 May 2012 the Animal Health and Veterinary Laboratories Agency
TB Research Group produced a report (www.basuk.com/files/pdf/120528_Updated_FINAL_REPORT_28th_MAY_2012.pdf) on testing alpacas. This was funded by and performed on behalf of The British Alpaca Society, the British Llama Society & British Camelids Ltd. The report focused on the performance of blood-based ante-mortem diagnostic tests to diagnose bovine tuberculosis in South American Camelids. Four serological tests (Chembio TB StatPak and Dual Path Platform – DPP - lateral flow tests, plus IDEXX and ENFERplex antibody ELISAs) as well as an interferon-gamma (IFNγ) release assay were apparently studied (although the alpaca owner the subject of this case study told us that Chembio apparently said they did not supply the Chembio stat paks)** note here AD can supply the emails from 2 sources from Chembio which state this**. Performance characteristics (relative sensitivities and specificities) of these tests were defined. The results were far from being conclusive and it was clear that further research would be required. Specific results were:
* IFNγ test can be applied with high sensitivity, but one would need to accept lower
• Animals with M. microti infection will give a positive IFNγ result to PPD.
• Antibody tests can provide high specificity and good sensitivity, but they are dependent upon skin test or on animals having severe/advanced pathology.
• Combination of IFNγ and antibody tests maximises detection of infected animals.
• Application of the blood tests as individual animal test plays to their strengths: clean-up of infected herds, tracing, trade/movement testing.
• Surveillance use (herd test): Blood tests are probably not applicable at present.
AD comments, “It is worth noting that a large number of animals for this research came from ‘information’ given by the alpacatb group and not actually studied by the AHVLA. It seems that this data may have been supplied by questionnaire. It is for this reason that I also think that the data is unreliable. In this research bovine tb was confirmed only with VL and very few animals came back with confirmed tb. In scientific terms this is highly unreliable and unspecific. I found out that frequently other bacteria do grow on the tissue culture plates but the owners are never informed of these as they are not identified and they are only looking for bovine tb. Could it be these other bacteria are causing the false positives?”
AD continues, “The problem is also that they won't test the other animals and they won't justify why they are testing the rest, ie. where would they get TB from with NVL?’ Surely if your herd is put under legal restrictions they should give you a written statement as to why they think your other animals have bTB?”
AD only received £750 compensation per animal. She does not consider this is a fair price for killing such good quality young animals (2 and 3 years olds) and ones with rare colours and a rarer type. She says, “Older and non breeding animals should only get about £250. Maiden females and potential stud males ie registered as such should be paid £1000. A proven male or female but they should at least pay the cost of a good stud, eg. £1500. It’s easy to prove a breeding animal via the herd book”.
AD says, “What is dreadful is that I offered Defra the chance to take further blood to progress research from the animals waiting slaughter. They only have test data on serological tests on 6 year olds (plus or minus 6 months), no pregnant animals etc and certainly not on older stock. On the actual blood tests themselves it is interesting it seems that they are using a modified Brock TB stat pak, which has been researched to show a higher false positive rate on young badgers. It could be the same for alpacas at both ends of age. Badgers don't make it to old age. You can guess what Defra says.... No! The single skin test is most specific at 90 hours (but they choose to test it at 76 hours), as well with comparative most specific at 76 hours. I cannot believe they turned me down on offering x rays, endoscope in lungs and body cavity, blood tests tissue cultures offered as well as ultrasound to prove they don't have TB. They said all it would be treated as would be a false negative”.
AD says, “It is unfair that other alpaca owners who refuse to have theirs tested are allowed to do this or so I thought! Knowing what I do now I am not surprised and I wished I had just isolated them and not allowed the tests. It is not like what many farmers say that we are burying out heads. We have undergone stricter testing with very poor compensation and with un-researched tests”.
Many alpaca owners are against the tests because Defra and the BAS will not supply the data they say they have about the combined skin tests and stat paks. They don't have them. My friend had two alpacas. One was 10 months pregnant. It failed the test, like my pregnant girls, and the other passed. She got a caesarian section done. It was mated to an American champion. It had NVL and the baby died 3 hours later, a much needed female. One guy lost 64 of his alpacas and, again no sign of bTB in any of them. Defra say there are no false positives but research shows there are. Defra is still claiming that all of those 91 alpacas must have had bTB because they failed a blood test but legally they can’t because no evidence of bTB has been found and the testing regime was not validated. In legal terms tissue culture is the only way to prove it and DEFRA’s inability to detect any infected alpacas in their herds when using the OIE(International) approved gold standard i.e. ‘Version adopted by the World Assembly of Delegates of the OIE in May 2009 OIE Terrestrial Manual 2009 1 C H A P T E R 2 . 4 . 7 . BOVINE TUBERCULOSIS’, which means that an animal is only found to be infected with TB if it, after the autopsy and the culture shows a positive result”.
AD was far from happy with the way the test was carried out. She said, ‘I was disgusted when they came to me and said that I had all boys. They don't have ear tags but have microchips, which they didn't check at first when I complained about incompetence. They don't calibrate digital calipers, which is a disgrace as they can go out of calibration by around 2.5mm. Don't get me started on blood taking, reading from a book but never attempted! Alpacas don't have veins that are easy to find. They did not wear gloves. They had alpaca spit down their arms and hands and this spit can carry the antibodies that they were checking for. They left syringes on the dirty floor. They rubbed their dirty hands on the skin of the animals’ necks just where they were going to put in a needle. They held the needle, still with dirty hands. They made about five or six attempts with each animal. They then sent the blood off un-refrigerated in the back of their van. Chembio says whole venous blood should be refrigerated in transport on their cassette inserts, but Defra says room temperature is fine? They could not tell me what stat pak was used. They could not provide temp records for the blood or assays. They could not provide the individual stat pak number, just a batch number, which cannot be traced. I'm being lied to and they are covering up their mess, ie not reading research before saying tests are validated. They say there is data available to the public but they have admitted to me in writing that they don't have it.’ The whole sorry saga is clearly an absolute shambles.
What worries AD is this recent statement from Defra.
6. Development of further measures for dealing with the disease in species other than cattle (e.g. camelids and goats)
Measures we are considering with the industry include compulsory blood testing of TB-infected camelid herds under movement restrictions and any animals traced from those herds, enhanced voluntary TB testing of non-restricted camelids from as soon as possible in 2012 or early in 2013, updating AHVLA’s guidance on TB in camelids and reviewing movement restrictions for all non-bovine species to ensure current arrangements are appropriate.
AD says, “As with Defra they are not stating what blood tests are to be used but if it is the same combined test as used on my herd god help the owners!”
AD continues, ”We had no choice on the blood test. My advice is do not do a skin test and blood test until the tests have been researched or use a different type of blood test than the stat pak. I don’t have issues with the other blood tests as stand alone tests. There are serious flaws, which we told to Chembio. The next day the camelid stat pak was off their website in the US. It has not been approved or validated by the US Defra.’
AD is quite right when she says there is not enough help for owners of animal caught up in the wretched bTB policy. Animal Health has little genuine interest in the welfare of animal owners or their animals. They are interested only in achieving their targets, spurred on by a policy that is causing utter misery to anyone who has the misfortune to be caught up within it.
AD concludes by telling us that she understands the big West Sussex herd where so many animals were slaughtered in Spring 2012 (and which supplied so many animals locally and further afield), ‘are being investigated. She says, “The American owner was apparently a vet and in his seventies. He had to give up the alpacas as he was retiring back to the US and could not take the alpacas back. His animals were pretty wild as they were not handled much and he had let their health deteriorate. They were in appalling condition. His land was on an annual rental lease and was up for sale. It was a bTB strain not previously in the area but was from the South Downs. There are about 40 young females left who are only one and two and some were left in appalling conditions which I reported. I have since checed up on them and they were back in the fields after passing the dreadful tests. It is hard to understand how Animal Health let these animals stay on piles of droppings with no straw bedding considering that is where the animals that had been slaughtered had been kept. It should have been thoroughly cleaned out and disinfected. Now the alpacas are in the fields there are cattle in the unclean sheds!”
AD wants the right to be able to vaccinate her animals. As they are not within the bovine group, presumably they are not subject to the same EU regulations. Why is vaccination not being offered to camelid owners? Badgers are being vaccinated now against bTb so why can’t alpacas? She also wants people to be vaccinated as well as this would reduce the already small risk of catching bTB from alpacas. Edwina Thirkell, Animal Health Regional Operations Director, England, told her that if there was a big risk that she would have been forced to kill her animals and they did not deem alpacas as a big risk.
More information from other breeders affected can be found in the Autumn Alpaca World Magazine. http://issuu.com/alpacamagazine/docs/autumn_12
AD’s alpacas can be seen at the You Tube link: http://youtu.be/MZTQaCTrLmk ‘Alpacas slaughtered by Defra’ – they were family pets and did not have bTB. They were slaughtered using the captive bolt method as alpacas have softer skulls and Defra stipulated the bodies had to be in Winchester by 10am.