TB tests

Re: TB tests

Julian Earl — Wed, 16 May 2012 18:32:04 GMT

Yep, that's a salutary post from Sarah and I feel a bit more wary now because of that post alone. All the same, it smacks of a legal loophole for the farmer rather than a scientific flaw in the procedure but I understand the problems and personally will think at least twice before going down the two-vet route.

Re: TB tests

Hannah Wynne Richards — Wed, 16 May 2012 16:43:19 GMT

I agree with every word Sarah has said

Wynne

Re: TB tests

Sarah Wheeler — Wed, 16 May 2012 13:42:00 GMT

I work in west Wales, where TB is a serious (massive) issue. We take it very seriously, much more seriously than some of you, judging by the posts I've read.

To answer the OP, we have been told by our AHVLA office that we are not to read other vet's TB tests except in exceptional circumstances, and I never would. I have been asked to, and my answer is always no. (The one exception was when the vet who had done the first day of the test had actually died on the Wednesday. That was a very hard test to read.) There is just too much TB in this area, and there is too much at stake. We regularly find reactors and probably 15% of our clients are under restrictions. So the prospect of finding a reactor is a very real possibility, and trust me, if I read a test for another vet and there was a reactor, the client would complain. Of course they would, and I wouldn't blame them, because I would do the same thing if I thought there was a chance the animal would be retested and pass. Do you recall the case of Shambo the sacred bull? Our practice wasn't involved in this, but it wasn't very far from here. It was a big deal; there was some issue in the way the test was carried out, and the owners refused to have the animal slaughtered and it ended up in court, and a big stand off on the farm, and the animal being taken off under warrant. (And it had visible lesions.)

The AHVLA are currently doing spot checks on the OVs in this area. Every week we have to submit a list to the local office of all the tests scheduled for that week, and they are turning up on the farms to check on us. I have no doubt that they are trying to catch vets out.

I am also very sad to hear that Leeds AHVLA are admitting they think you make numbers up. I think they (and some of you maybe) need reminding that a TB52 is a certificate and signing it has implications. You have been very lucky not to have TB in Leeds, but with that attitude, it may not be long in arriving and spreading.

Re: TB tests

Neil Wheadon — Sat, 12 May 2012 23:24:52 GMT

[quote user="David Mills"]I think it does depend on your relationship with the farmer. Most will have been clients for a while, and are bonded to the practice, meaning for the most part they will trust what you say, and how you carry out the test. Most see it as a necessary inconvenience (albeit a couple of visits thrown in); most don't want TB. It is disingenuous for those with reactors to challenge the decision as they will need to be retested and (I don't have the figures, but I bet they're high) will usually test positive again[/quote]

This is also false I'm afraid

It's really quite common for a farmer to refuse to have a reactor removed or ask for a retest and in my 11 years there was no difference between OV, VO, VI or a lay tester doing the test, if it's valuable or they want to keep it farmers will try. The reason that they are persuaded to have them removed is because the certification and the testing protocol was sound and so they can be persuaded that the reactor needs to be removed. As the testing vet you just don't see this side of TB work and it's hard, as after all I hate to see a good cow go to slaughter too. I had tremendous faith in the quality of OV testing in the area I worked and could use this as a persuasive arguement.

If they were re-tested would most fail again? This is debatable and as someone said this is a screening test with 85% sensitivity, so 15% of cattle may pass next time. Add to the fact that about 45% of cattle are NDL at PM having been positive on the skin test and a fair few re-tests will pass the skin test, but some of these will be silent open cases and having dealt with 2 open cases in 'In Calf heifer 'groups in 2010 where 90% of the followers were slaughtered it will knock a farmer back years .

So if the farmer was allowed to retest and the cow cleares what does that do to the credibility of the vet who did the test? If you are an employee of the state, no problem as they may not see you again, but as a vet in the OV practice.....

I am convinced that the regulations are there to protect the OV. The drones (that was me...bzzzzzzz) at AHVLA move heaven and earth to prevent any retesting. This protects the integrity of the vet doing the test it's a simple as that.

Re: TB tests

Luke Edwards — Sat, 12 May 2012 22:36:13 GMT

2. [quote user="David Mills"]

IIn relation to the OP, many a time I've read other peoples' tests with the same callipers without a problem. The idea that you need some permission from an AHVLA drone is false,[/quote]

This is not true - look at the "Instructions for OVs" issued by Animal Health.

" 2.The complete tuberculin test must be carried out by the same Official Veterinarian (OV) unless there are exceptional circumstances. OVs therefore should not commence a test that they know they cannot complete.

3. If the same OV is not able to perform and read the test they must notify AHVLA. In these circumstances a note must be made on the test report (TB52)."

http://animalhealth.defra.gov.uk/External_OV_Instructions/TB_Instructions/Skin_Test/Skin_Test_Day_One.html

As for the quote about "Destroy a Farm" - as a student I visited a TB riddled farm where not only every bovine was slaughtered, but every animal - cats, dogs, chickens-the lot. I've never forgotten it. As a vet I've condemmed a fair few cows to death myself, and seen it cause a lot of heartache. TB testing maybe monotonous - but it is also deadly serious.

Luke Edwards

Re: TB tests

David Mills — Sat, 12 May 2012 13:18:40 GMT

[quote user="Thomas Johnson"]

However, the issue as I see it is that there is a protocol for doing the test, any deviation from that protocol - even if we know that scientifically it won't make a difference - means that the test hasn't been done correctly. If a farmer can show that the test hasn't been done correctly, and show that his income will be adversely affected by the result of the test, the likelihood is that the results will be quashed and the test will have to be done again. If one farmer is successful, other farmers may be tempted to appeal against decisions. Any decision to re-test means that reactors are in the herd for longer increasing the risk of spread of infection.

[/quote]

I think it does depend on your relationship with the farmer. Most will have been clients for a while, and are bonded to the practice, meaning for the most part they will trust what you say, and how you carry out the test. Most see it as a necessary inconvenience (albeit a couple of visits thrown in); most don't want TB. It is disingenuous for those with reactors to challenge the decision as they will need to be retested and (I don't have the figures, but I bet they're high) will usually test positive again.

The technicality argument reminds me of speeding fines where people can get off if fro instance the speed gun hasn't been calibrated that morning; they were still speeding, they know it, but - to the wet dreams of lawyers countrywide - they can get off because of some pointless technicality.

However, I would, the way the AHVLA are going with this, expect that challenges will only become more widespread if a government contractor is carrying out the test - vets the farmers don't know, don't trust, doing tests countrywide.

Re: TB tests

Thomas Johnson — Sat, 12 May 2012 11:28:38 GMT

I haven't done TB testing for a few years, but in my first job I booked in all of the testing for our branch, and we had about a dozen farms on 60 day testing at any one time, and everyone else on annual testing, and was usually personally testing several hundred cattle a week. TB testing is a dangerous job, I'm amazed more vets don't have hands broken in crushes, and in some herds it is virtually impossible to do the testing as instructed.

Re: TB tests

Hannah Wynne Richards — Sat, 12 May 2012 09:57:15 GMT

If things go wrong, it won't be veterinary surgeons judging you, but DEFRA bureaucrats-so decisions aren't necessarily going to be made on the basis of scientific validity, more political convenience TB is a publically emotive disease DEFRA veterinarians can say until they're blue in the face that human and bovine strains are different,but I doubt you'll find a doctor who will stick his/her neck out and say that milk from affected cows is totally safe to drink Any of you remember the furore when BSE was discovered? No scientific justification for assuming that because scrapie had jumped from sheep tocattle it would suddenly become virulent in humans Time has proven it wasn't-very few human cases This didn't stop a public/political outcry that nearly destroyed cattle farming -and landed the taxpayer with a massive bill under the > 30 months scheme If the public discover that TB tests aren't being done strictly by the book, there could be a similar backlash against milk Just cover your back-refuse to read someone else's test unless you have permission from DEFRA and there's a sufficiently valid reason like serious illness or family bereavement to justify asking

Wynne

Re: TB tests

Julian Earl — Sat, 12 May 2012 09:30:03 GMT

[quote user="Neil Wheadon"]

Hi Julian

... AHVLA last year couldn't remove a gamma positive reactor on a blood tst because the tester used 2 tubes to get 7ml of blood rather than one, it's that black and white. [/quote]

I find that a bit hard to believe to be honest, at least that that was the only factor. There are no scientific grounds for the decision as described surely?

[quote user="Neil Wheadon"]

When I say that AHVLA think that many vets don't do the job properly, this is certainly the view of those making the big decisions. Maybe many is too strong a word but there is that perception. Two years ago I was quizzed heavily as to why I didn't measure everything on day 2 by a senior member of management (It's not in the regulations, but it was a lip biting experience)

The original question was 'would you read on day 2 for another vet?' Imagine the scenario. Day One, injection day. It's a straightforward job really, catch the cow, clip the neck, chat about the football, enjoy the sunshine. Day Two is totally different, it's reasonably jolly until the first reactor, now imagine it's the best cow in the herd, last of the line and all that, worth £10000. You're a new graduate and maybe you've found a hatful of them? They're all close to calving (and anecdotally dry cows do react more don't they) you're the farmer and you don't want to lose them? Use a solicitor? Why not, Mr Jones at Castle Farm did last year and won. As the vet you'll get dragged in because you did the test and signed that you did it and you signed to clinically examined them too. (More tricky to justify on day 2 when they are moving through the race a little faster)

My plea here is don't give them that opportunity, believe it or not AHVLA will back you up provided you've done the right thing.

Neil

[/quote]

The scenario you descibe should not be a problem whoever has done the test. If they have lumps, they have lumps. As long as a standard method is used to measure the skin - part of the training - then the fingers on the calipers don't, or shouldn't matter. Otherwise, how does one know that the second test correlates with the first? What about a third test? The prime source of variability in the test comes from the animals, not the calipers.It is a screening test after all.

Re: TB tests

David Mills — Fri, 11 May 2012 20:36:13 GMT

[quote user="Neil Wheadon"]

and you signed to clinically examined them too.

[/quote]

No you don't. You sign to say that they appeared clinically well, without a clinical examination. The guidance notes are very clear on this: a clinical examination need only be carried out on those animals that appear unwell. This does not, legally, count as a clinical examination having been carried out on every animal, which you imply. The two are quite different.

It would, surely, be for a judge to decide if correct protocol was followed - and, in this OP, if exceptional circumstance was present. This, I assume, could be anything from a calving to a personal matter; it is not for DEFRA/AHVLA mandarins to decide - much as they would like it to be. As for the perception by AHVLA, well, much good may it do them; I suspect they'll be far more issues with roaming hordes of Spanish vets TB testing up and down the country as MHS soon found (and still find) with abattoirs. Funnily enough, it might actually be healthy for LA practice to throw off TB testing - it's a poorly compensated mind-numbing job that only brings with it grief from the ivory towered masses who've never set foot on a farm and wouldn't know TB if it mooed in their face.

Re: TB tests

Neil Wheadon — Fri, 11 May 2012 19:14:38 GMT

Hi Julian

Yes these are fair points

In my opinion there has been a hardening in attitudes to TB testing over the past few years and this has been partly driven by many farmers appealing reactor removal. In this respect AHVLA very much stand behind the OV in stating that the certificated TB52 is the legal document and the figures there are correct. What then happens in some cases, is that the way that the TB test was performed is looked at. This is set out very clearly but if there is any deviation from the standard protocol then the farmer will win the case and this will set a precident for other challanges to TB testing. AHVLA last year couldn't remove a gamma positive reactor on a blood tst because the tester used 2 tubes to get 7ml of blood rather than one, it's that black and white.

My plea here is don't give them that opportunity, believe it or not AHVLA will back you up provided you've done the right thing.

Neil

Re: TB tests

Julian Earl — Fri, 11 May 2012 17:09:38 GMT

I agree with Nick David.

I am puzzled by the apparent problems caused by a different person reading a test on the second day. It's not as though the calipers are a precision tool and the same person won't use the same pressure every time. Many years ago, I was the lucky soul who identified the first TB in Lancashire for a long time - fifteen years maybe? The bovine reaction was "only" +4, and I could easily have squeezed a bit harder to make it a +3 and put it through as an inconclusive instead. As it was, I underwent the third degree when I reported it as a reactor and because TB "didn't exist in Lancashire", MAFF re-tested it anyway. It failed again, was culled and culture-positive. The point is that it doesn't matter who does the second reading as long as they are conscientious and check every lump. Just how ruthless DEFRA will be about readings is their decision.

Re: TB tests

David Mills — Fri, 11 May 2012 14:20:01 GMT

[quote user="Neil Wheadon"]

[quote user="Michael Woodhouse"]We were categorically told that they knew we would make up numbers.[/quote]

Which is why vets will potentially lose this revenue stream through tendering as it is acknowledged within AHVLA that many vets simply don't do the job properly. AHVLA has lots of lay testers - trained animal health officers

[/quote]

I assume you have some data to back up this unmitigated slur on TB testers by yourself and AHVLA, because an independent quality control inquiry into TB testing in to mid 2000s (I assume you're aware of this?) found the quality of the test and testers to be more than adequate for disease prevention and control. Is this, woe betide, the opinion from within the drone-filled ranks of the AHVLA?

You'll certainly be aware Mr Wheadon that new TB testers from 2008 onwards (possibly before) now have to do a supervised test of at least >20 cattle with a lay TB tester from AHVLA. Anecdotal, but by the time they got round to doing mine 2 years after the course, I'd done 30 or so tests already; my supervisor had done 3 in the last 3 years.

In relation to the OP, many a time I've read other peoples' tests with the same callipers without a problem. The idea that you need some permission from an AHVLA drone is false; or that you'll be struck off even more false; it's a silly principle drummed into people by self-preservational AHVLA mindthink - as elucidated by Mr Wheadon - and as others have said its permitted under the testing regime, in a rare nod to real world reality outwith the civil servant bubble. Also the idea of 'closing the farm down' is another dwarf threat unless you're in a hotspot - all the IRs or Rs I had AHVLA simply told to isolate (without checking if they had done - farmers didn't) and retest in 3(? - been a while) months. That was a 4 year parish. No movement bans or close downs or market closures. "Destroy a farm" - this is the all or nothing ivory tower speak; you can assume most things like this that come forth from animal health are products of arts graduates treading water before they can become a parliamentary researcher for an MP.

Re: TB tests

Malcolm Ness — Fri, 11 May 2012 14:02:58 GMT

[quote user="Neil Wheadon"]I've smiled and nodded and your various comments Malcolm but this one just isn't right.[/quote]

I am only reflecting personal experience. I am not trying to suggest that all civil servants are devious, lying barstewards because I know that not to be the case. However, I have learned from bitter experience that even very senior veterinary civil servants are prepared to deny unwritten discussion to cover their own arse.

Re: TB tests

Neil Wheadon — Fri, 11 May 2012 12:02:37 GMT

[quote user="Malcolm Ness"] the civil servant, too, will drop you in it without a second thought[/quote]

I've smiled and nodded and your various comments Malcolm but this one just isn't right. I thought before working for SVS/AH/AHVLA that the vets were a different species but they aren't. Telephone conversations are recorded as notes and the vast majority are there to help, you don't need to write a letter in every case. There were many times that I auditted TB test charts when they came into the office and many had mistakes. These included the Avian and Bovine numbers placed upsidedown so creating reactors and tests read at severe when they should have been at standard. In some cases innocent cows are still walking about with a reactor tag I bet. We would call the vet involved and question it, with the result that the fax machine was quite busy at times with a corrected test chart. However with iSAM this friendly checking stage will be removed so it's a warning to testers to make sure the information is OK when submitted

Re: TB tests

Malcolm Ness — Fri, 11 May 2012 07:21:55 GMT

[quote user="Luke Edwards"]and dumping you straight in it[/quote]

And remember, any conversation with a civil servant (even if that civil servant has a veterinary degree) didn't happen unless it is confirmed in writing. If things don't go well, the civil servant, too, will drop you in it without a second thought.

Re: TB tests

Luke Edwards — Thu, 10 May 2012 22:27:50 GMT

Don't do it. TB testing involves an element of certification. False certification is an disciplinary offence. Several Vets have been disciplined for incorrect approaches to TB testing in recent years. Furthermore if the farmer knows that the test was done incorrectly, and is not happy with the result, then he will not hesistate to inform Animal Health that the test was not done properly, hoping to get it declared void - and dumping you straight in it.

Luke Edwards

Re: TB tests

Thomas Johnson — Thu, 10 May 2012 17:22:54 GMT

[quote user="Hannah Wynne Richards"]

Those Radnorshire sucklers

[/quote]

Mostly on the other side of the border in Shropshire and Herefordshire, but very much the same!

Re: TB tests

Hannah Wynne Richards — Thu, 10 May 2012 15:57:37 GMT

Those Radnorshire sucklers

Wynne

Re: TB tests

Thomas Johnson — Thu, 10 May 2012 15:07:10 GMT

[quote user="Michael Woodhouse"]

TB testing gets in the way of profitable work and only contributes a few % to turnover. I'm sure I could more than make that back up. (we are an 80% large animal practice)

[/quote]

My first job, in the Welsh Marches, was a six vet practice, with enough TB testing for one full time vet, it was shared equally amongst us. I imagine it didn't add much to practice profit, but it did mean a 2 in 6 rota instead of a 2 in 5 rota (we did a first and second on call).

Re: TB tests

Neil Wheadon — Thu, 10 May 2012 09:52:13 GMT

[quote user="Alan Tevendale"] It still worries me that the majority of TB breakdowns in 4 yearly testing parishes are found at slaughter rather than by testing.[/quote]

Annual testing is being expanded, in the South West there are no 4 yearly testing areas any more. Other areas are to be included http://animalhealth.defra.gov.uk/managing-disease/notifiable-disease/bovine-tb/tb-testing-intervals.asp it's a logical progression for the rest of the country to follow suit? When a SLH case is found in a 4 yearly area, gamma testing etc is employed.

For me the frustration of TB was the lack of a targetted approach. Many breakdowns and i dealt with 100's could be wittled down to a group that had been exposed to infection and it was possible in many cases to target test this group leaving the rest of the cattle alone, saving thousands and thousands of pounds. In this respect there should be an oppertunity for OV's to get involved with the whole process and many of the practices I liaised with helped with this by marking charts with groups and writing notes with the test charts that were hugely helpful. Yes TB testing is dull monotonous work, but with a more pro-active approach at least you feel that as a vet you are helpin,g which was one reason why I think TB testing should remain in vets hands as anyone can clip, measure, inject but it takes a professional to look at the broader picture

Re: TB tests

Colin Thomson — Thu, 10 May 2012 09:05:32 GMT

With my SPVS hat on I've been to a couple of meetings around the issue of TB tendering. It transpires that for a few large practices (about 30 as I recall) based in the South West its a really big thing - 60% of the turnover of some. If my memory serves these practices currently get paid over 50% of all the money paid out on TB testing. For the rest of the country, for most practices loosing TB wouldn't be a huge issue. I was talking to some vets from Northumberland at one meeting. Big farm animal practices with big suckler herds - many hunderds of cows per herd from what I gathered. They wouldn't mind too much if they lost the TB testing. They'd be happy to see it done by Eastern European vets or lay testers - they just didn't want it done on their farms by their neighbours.

Colin

Re: TB tests

Alan Tevendale — Thu, 10 May 2012 07:35:15 GMT

I have to agree with Michael that TB training in Leeds was certainly more lax than other animal health offices. Most of my contact is with East Midlands and they treat the whole situation extremely differently to the 30% or so of tests that we do for Leeds. It still worries me that the majority of TB breakdowns in 4 yearly testing parishes are found at slaughter rather than by testing.

Michael does make another good point. TB testing is not profitable. In areas with large numbers of beef herds where cattle aren't handled on a regular basis testing takes far longer than on dairy herds. I actually think we make a loss on testing. This then becomes something that we either suck up and get on with (and do properly), as we do at the moment, or give up entirely and have the job carried out by lay testers working on behalf of the AHVLA. Paying vets such as low renumeration for this work is hardly encouraging them to carry out the job without trying to cut some corners. I will certainly never ask my vets to cut corners on any job and wouldn't want them to feel that they should but I do get the feeling that there are vets out there that do.

Re: TB tests

Michael Woodhouse — Thu, 10 May 2012 00:26:37 GMT

[quote user="Neil Wheadon"]Which is why vets will potentially lose this revenue stream through tendering as it is acknowledged within AHVLA that many vets simply don't do the job properly. AHVLA has lots of lay testers - trained animal health officers[/quote]

They are welcome to it. TB testing gets in the way of profitable work and only contributes a few % to turnover. I'm sure I could more than make that back up. (we are an 80% large animal practice)

I don't like it, but I do it properly.

Re: TB tests

Neil Wheadon — Thu, 10 May 2012 00:14:54 GMT

[quote user="Michael Woodhouse"]We were categorically told that they knew we would make up numbers.[/quote]

I did disease report forms in the South West for 11 years, towards the end almost exclusively, and the impact on a farm of going under restriction was dramatic. The flying herd were particularly badly hit.

By not doing a TB test properly can destroy a farm, I've seen it.

Yes there is plenty of neck to check a measurement but the neck does not have the same skin thickness all over. I reckon that 1 in 20 cattle have thicker skin at the bovine site. I've measured many bulls and don't recall many at all having the same A and B measurements and this applies to suckler cattle too.

It's the close call ones that make a difference where a mm difference will make or break a test. There's a particularly nasty trap where in a confirmed outbreak if the reactor is NDL but a STANDARD reactor the farmer still needs 2 clear tests. In this situation you have to be spot on with the measurements as I saw multiple cases where 2 more months of pain for the farmer ensued, because the A/B difference was 5mm not 4mm.

It needs to be taken seriously, as a clinical vet now, I save a single animal, in the case of TB you are dealing with the business.

Maybe you can be lax in Leeds, but it will only take a single missed DL reactor that's an open case (and these can be subtle on skin changes as their immune system is worn out with TB) to spread it to the wildlife and the effects will be dramatic. In essence you need to be more vigilant than the South west as in the majority of cases the next test is only 60 days away.

Neil

PS To explain the DL reactor getting to Leeds. There are 2 factors

1) The more you test a herd the less sensitive the test becomes. This is why breakdowns occur so frequently at 6M tests as the immune system has had time to recover a bit

2) Cattle riddled with TB wil often be anergic so don't react to the test

When a farmer within a long breakdown finally passes, he/she is often overstocked and will have a window of 6 months to sell (before failing at the next test) and these cattle can go anywhere.