Badgers and TB

RE: Badgers and TB

Iain Richards — Wed, 26 Apr 2017 15:31:56 GMT

Nitrogen foam maybe the answer. I've seen videos of it for chicken huts, remarkably humane, and DEFRA were supposed to be testing it's ability to creep around a structure.

RE: Badgers and TB

Lucy Fleming — Wed, 26 Apr 2017 12:58:59 GMT

insecticides never seem particularly pleasant, either...

RE: Badgers and TB

Evelyn Barbour-Hill — Wed, 26 Apr 2017 12:49:18 GMT

[quote user="Lucy Fleming"]

That does seem to be based on some fairly old research with hydrogen cyanide, apparently experiments with carbon monoxide have been suggested but not really carried out.

[/quote]

Maybe they should be.... Yes, I know, political considerations make it impossible.

I feel that if shooting were carefully planned and competently carried out, it could be very effective. We would have to find something to keep the saboteurs out of the way though.

Funny, isn't it, mice and rats are killed every day with anticoagulant poisons that provide a slow and unpleasant death, but nobody seems to protest about that.

RE: Badgers and TB

Lucy Fleming — Wed, 26 Apr 2017 12:32:59 GMT

That does seem to be based on some fairly old research with hydrogen cyanide, apparently experiments with carbon monoxide have been suggested but not really carried out.

RE: Badgers and TB

Evelyn Barbour-Hill — Wed, 26 Apr 2017 12:30:16 GMT

[quote user="Lucy Fleming"]Because getting gas concentrations high enough, quickly enough in a sett is problematic, tending to expose animals to sub-lethal concentrations of gas. [/quote]

I see.

RE: Badgers and TB

Lucy Fleming — Wed, 26 Apr 2017 12:25:58 GMT

[quote user="Evelyn Barbour-Hill"]why not gas the setts, where we know the badgers will be in the daytime?[/quote]

Because getting gas concentrations high enough, quickly enough in a sett is problematic, tending to expose animals to sub-lethal concentrations of gas. Culling wildlife for disease control reasons doesn't mean we shouldn't kill them quickly and competently.

RE: Badgers and TB

Neil Wheadon — Tue, 25 Apr 2017 21:18:58 GMT

[quote user="Lucy Fleming"]But you don't have to be 'against culling badgers in infected areas' to recognise that the culls as currently designed are flawed to the point of most likely being ineffective.[/quote]

Page 38

Reasons for culling less than 70%

'Culling was not permitted on up to 30% of land in each pilot area. However, culling on the borders of non-compliant land holdings may have removed some badgers from them. '

That'll skew the statistics.

As usual for these studies a detailed and well researched report. I admit to skimming it trying to pick out interesting bits, but the conclusion was that shooting was very efficient. The vast vast majority of badgers were killed very quickly.

The issue as in everything to do with experiments post 'Thornbury Ring' is that you can't conduct a proper study, interference by everyone, farmers and protestors alike.

Neil

RE: Badgers and TB

Evelyn Barbour-Hill — Tue, 25 Apr 2017 17:59:08 GMT

[quote user="Lucy Fleming"]

[quote user="Michael Woodhouse"] I really can't see how a vet (or anyone with knowledge of the spread of infectious disease) could be against culling badgers in infected areas.[/quote]

But you don't have to be 'against culling badgers in infected areas' to recognise that the culls as currently designed are flawed to the point of most likely being ineffective.

"Based on the more robust estimate of effectiveness (namely, cull sample matching: see above, 4.2.1 - 4.2.5), we can be 95% certain that controlled shooting removed less than 24.8% of the pre-cull badger population in Somerset, and less than 37.1% of the pre-cull population in Gloucestershire."

"4.3.4. Based on the more robust estimate of effectiveness (namely, cull sample matching: see above, 4.2.1 – 4.2.5), we can be 95% certain that a combination of controlled shooting and cage trapping removed less than 48.1% of the pre-cull population of badgers in Somerset and less than 39.1% of the pre-cull population in Gloucestershire."

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/300382/independent-expert-panel-report.pdf

[/quote]

Assuming that the shooters in the studies cited were competent; and assuming that traps were not constantly being interfered with; why not gas the setts, where we know the badgers will be in the daytime?

RE: Badgers and TB

Lucy Fleming — Tue, 25 Apr 2017 16:44:31 GMT

[quote user="Michael Woodhouse"] I really can't see how a vet (or anyone with knowledge of the spread of infectious disease) could be against culling badgers in infected areas.[/quote]

But you don't have to be 'against culling badgers in infected areas' to recognise that the culls as currently designed are flawed to the point of most likely being ineffective.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/300382/independent-expert-panel-report.pdf

RE: Badgers and TB

Neil Wheadon — Sat, 22 Apr 2017 21:29:05 GMT

[quote user="Michael Woodhouse"]Cattle clearly are infectious to each other. We are 4 yearly testing and had a farm buy in a cheap cow that turned out to have TB. Spread to a number of other animals whilst it was on the farm. I forget the exact figures but I think we lost 9 cows to the skin test and 10 more to gamma interferon out of about 60 (1/3 of the herd).[/quote]

Really interesting.

Gamma testing certainly indicated here

[quote user="Michael Woodhouse"]My feeling is that very little transmission will be going on from cattle to badgers.[/quote]

You'll know if the infection has taken hold. Hopefully if the gamma has stripped out any potential cattle then this holding (and neighbouring) should test clear if it hasn't got into the wildlife. I can certainly appreciate your reservations about 4 yearly testing

Neil

PS Roger Evans articles in Vet Times are fantastic. His analogy of badgers and hares in the April 17th edition is thought provoking

RE: Badgers and TB

Michael Woodhouse — Sat, 22 Apr 2017 14:35:14 GMT

Cattle clearly are infectious to each other. We are 4 yearly testing and had a farm buy in a cheap cow that turned out to have TB. Spread to a number of other animals whilst it was on the farm. I forget the exact figures but I think we lost 9 cows to the skin test and 10 more to gamma interferon out of about 60 (1/3 of the herd).

My feeling is that very little transmission will be going on from cattle to badgers. In the endemic areas cattle are tested so frequently that they don't really get to shed significant levels of infection. Unless someone has evidence to the contrary I'm sure the disease is stable in badgers and spreads from badger to badger. Those badgers then pee on the grass and infect cattle (and deer). Spread from the urinary tract is the big problem in badgers.

The other thing I don't think we've talked about is genetics of TB resistance in cattle. There are now validated genomic proofs for TB resistance. We know that a lot more cattle are exposed and don't go down with disease, with it running in other families.

Farmers want to blame badgers and the government for protecting them. Lots of people seem against culling sick badgers. Everything muddied by legislation. I really can't see how a vet (or anyone with knowledge of the spread of infectious disease) could be against culling badgers in infected areas.

RE: Badgers and TB

Neil Wheadon — Fri, 21 Apr 2017 15:28:16 GMT

[quote user="Iain Richards"]I'd still maintain that bTB is quite a complex disease to comprehend, its testing, its immunity, its pathology and infectivity.[/quote]

Because, there is so much contradictory and frankly wrong information about. It took me 4 years to really feel I was getting to grips with it.

An absolute classic is biosecurity, wash those tyres, clean this machines and this was part of the regulations for isolation units. The thing is, TB isn't passed faecally.

TB research is much about trying to prove a negative. So much of the research is based on this, it's almost impossible (see above, lots of faecal experiments, none found)

[quote user="Iain Richards"]The transmission remains an issue, I personally suspect its a recently infected cow, multiplying bacilli in the pro-paharynx, depositing it on grass, then eaten by foraging badgers, who pee on the grass eaten by cattle.[/quote]

1) If that's the case how many vets farm workers bolusing cattle or even TB test are in danger? We're being snorted on all the time, yet human cases are rare.

2) Fat animal slaughtered, TB found, rest tested, nothing found, yet they had been intensively housed together for up to 2 years. It's not that contagious

3) Your example is 'theoretical' ,is what you suspect reality? If a cow deposits bacilli on grass what's the chances of picking up an infected dose. If you really dig into cases of TB, many that are visibly lesioned are in the oropharynx. That's because we test so often that TB doesn't have a chance to get further. It takes about 2 years to get to the udder and by that time we've tested the animal. However how many are open cases? Now that is a fact very hard to find and it is a very small number.

4) Your example may work for a clean area, when an open cow case is transported to a clean area, but that isn't the reality of practically all of the TB outbreaks (Including Exeter) Even in open cases and I think research (my brain is rusty after 5 years) has shown that when you mix an open case with clean cattle in a shed, horizontal transmittion is unlikely.

Neil

RE: Badgers and TB

Richard Carter — Fri, 21 Apr 2017 14:24:38 GMT

TB may be multifactorial but the complexity of the UK problem has been manufactured by people with certain agendas.

TB is also a disease where the logic for control has reached hysterical levels with far too many people having a say in what originally was a control to reduce inefficiency and wastage of sick animals.

As others have said by the 1970's, TB was almost an extinct disease. Then budgets were cut for testing, badgers were protected and the government wanted a 'green' vote, not the 'self sufficiency feed the nation' one.

Risks to human health are low - almost all milk is pasteurised and then diluted to such a degree while similarly the level of TB in the actual meat muscle even in an animal infected with TB is very low.

TB from a human safety point could be controlled by shifting the emphasis to meat inspection and proper preparation of meat. Dairies producing unpasteurised milk products would need other controls and tests but if milk is pasteurised, there would be very little other checks needed.

Also second/ third/ support the idea the badgers are removed from the protected list and that infected setts should gassed and then filled/ destroyed to reduce contamination to the next lot of badgers that would take up residence. It is a nasty disease for cattle, badgers and other wildlife but perhaps we could act more sensibly if we weren't dealing with EU and historical rules for control (WHO/OIE) and deregulated the disease from one of international importance to national or even local importance.

The alternative is for farmers to switch to growing trees and tourists and letting hundreds of years of expertise and bloodlines go which would be a sad day.

RE: Badgers and TB

Iain Richards — Fri, 21 Apr 2017 11:09:44 GMT

Neil, I take your point and I know of similar cases (true closed herds). I'd still maintain that bTB is quite a complex disease to comprehend, its testing, its immunity, its pathology and infectivity. Especially to the layperson (or some vets) The smoke and mirrors, I'd agree with as much of the research seems contradictory and what is presented is selective.

The transmission remains an issue, I personally suspect its a recently infected cow, multiplying bacilli in the pro-paharynx, depositing it on grass, then eaten by foraging badgers, who pee on the grass eaten by cattle. As you say, from 50 cases to today's picture is a national disgrace and the dichotomy between killing one reservoir species and not the other is not logical.

RE: Badgers and TB

Iain Richards — Fri, 21 Apr 2017 11:01:05 GMT

Native vs non-native. Non-native species create pressures on ecosystems by being separate to the normal regulation systems in that ecosystem. This can be as a result of not being recognised as prey/predator or by introducing disease (Pacific lion fish in the Caribbean and grey squirrel in GB, respectively). However the same sort of damage can result from a native population where the normal controls on population have been removed. So reduced wolf population in the USA has increased the coyote population and they in turn have decreased the foxes. As badgers now have no non-human predators and conditions have favoured their expansion, they are exerting an unchecked pressure on the ecosystem, just as if they were introduced. The re-introduction of white-tailed eagles might well be causing similar problems with ground nesting waders.

RE: Badgers and TB

Lucy Fleming — Thu, 20 Apr 2017 09:57:51 GMT

[quote user="Jo Dyer"]information from NZ regarding a different wildlife reservoir. [/quote]

I think the information from NZ is not particularly relevant, sadly, due to the practical differences in culling methods. The Brush Tailed Possum is an introduced species, which is extremely destructive to native tree species and native birds (disturb nesting birds and eat eggs and chicks). Badgers may be voracious eating machines, but they are a native species and we can't really justify wholesale destruction in the same way.

New Zealand also has no native mammal species (apart from some bats) - which means that baits and poisons can be used, and the only other animals that will be damaged are also non-native pests (rats, stoats etc). I'm not sure of exact comparable budgets, but I assume that dropping baits is relatively less expensive (per head of pests dispatched) than setting up shooters.

RE: Badgers and TB

Jo Dyer — Thu, 20 Apr 2017 09:43:11 GMT

[quote user="Neil Wheadon"]

[quote user="Iain Richards"]The trouble being that it is an incredibly complex disease to understand[/quote]

It's not. There is so much smoke and mirrors in the whole debate.

[/quote]

It does seem to be a subject mired in conflict and misunderstanding. I am beginning to realise why even vets are confused, so what hope is there for the general public, and people like Chris Packham and Brian May?

So, to counter the Independent Scientific Group trial of 2007, we have a report from 1975 of the Thornbury Ring, a report from Ireland from 2013 or so, and information from NZ regarding a different wildlife reservoir.

The ISG's statement was so sweeping, that by saying 'badger culling cannot meaningfully contribute to the future control of cattle TB in Britain' it has pretty much ruled out any control of the wildlife reservoir until we get a better study (and I'm not holding my breath on that one). Rather than saying 'culling methods as used in this trial' which would have been more scientific even if still inaccurate.

I love wildlife. I just think that, around here at least, we need to get a balance back (then I might see my beloved hedgehogs again).

[quote user="Neil Wheadon"]Take the badger off the protected register and the farmer will sort it out.[/quote]

Yes. Chances of it happening? Hmmm.

RE: Badgers and TB

Neil Wheadon — Wed, 19 Apr 2017 23:34:24 GMT

Hi Ian

[quote user="Iain Richards"]The trouble being that it is an incredibly complex disease to understand[/quote]

It's not. There is so much smoke and mirrors in the whole debate.

I looked into over 1000 TB outbreaks, interviewing farmers, mapping cattle locations and thanks to vets doing TB tests marking the epidaemeological groups on test charts could track which cattle were affected.

Cow to cow transmittion is incredibly rare. I documented one case where a dairy herd couldn't get rid of TB and I ended up clinically examining 4 cattle and sent 3 for slaughter. 2 were visible lesioned reactors (This is the clinical bit on a TB test) This action was unheard of in the division I worked in.

What chance cow to badger? Cows don't cough down badger setts and bovine dung isn't infective and boy has a lot of research gone into trying to prove that.

Of the other 999+ the cause was wildlife. Different holdings suffering TB outbreaks having a shared piece of woodland. Closed herds surrounded by arable land going down with TB. The gradual movement of TB down a valley as it picked of a couple of farms a year as it spread between closed herds. The zero grazed 500 cow dairy herd that regularly had 25 reactors but always in the heifers grazed outside, whilst the indoor herd never had a reactor.

At any one point there are maybe 60 projects into TB looking at spoligotypes, modes of transmittion, etc but to my knowledge cow to cow spread hasn't been shown to anything more than less than negligible. It's like fiddling whilst Rome burns when for anyone who lived and breathed this the reason is obvious, the wildlife reservoir.

It's too late now. From less than 50 cases this disease has spread from the extreme South west to Yorkshire, vaccinating badgers is a joke, maybe 16% partially respond and you have to trap them to do that. (Ireland did show that oral baiting had some effect, but there was a hue and cry about some badgers getting far to much, that's the atmosphere, this disease lives in) Christian Glossop is doing a fine job in Wales but as far as I can see all they are doing is test, test and test again and trying to keep the wildlife (badgers) out of the farms which is very very difficult

I've just checked the interactive map in the area I knew well, it's depressing, with so many dead cattle and farmers locked down with restrictions, nothing has changed in 5 years.

The rest of your post I agree with. I liaised closely with the TB guru in the South West 5 years ago and we both agreed. Take the badger of the protected register and the farmer will sort it out. Farmers want clean badger sets as it keeps the 'dirty' badgers away. Only then will we make progress.

Neil

RE: Badgers and TB

Iain Richards — Wed, 19 Apr 2017 21:51:01 GMT

Hi Jo, you've asked some reasonable questions, particularly education for non-farm vets. The trouble being that it is an incredibly complex disease to understand, even more so when you study it in wildlife. Then you add in the political dimension, plus a cognition bias and it's no surprise that views are entrenched. I'd agree with the other replies, but one of the most difficult elements is the precise transmission. It's likely to be from a contaminated environment, but it's currently unknown.

What has to be understood by all vets is that badgers are a true reservoir host. That is precise definition - a population where a disease is maintained without further introduction. In fairness, cattle are a reservoir for badgers. Other wildlife in the UK are spill-over (although fallow deer, being herding animals are a grey area). Previous reports e.g. Krebs have established that badgers are a major source of infection for cattle.

Vaccination - it's a nice idea, but BCG is not a great vaccine, it only protects against spread within the animal, it does not create an immunological protection. It was introduced to stop humans getting spinal or cerebral TB. The decline in human TB is most due to better nutrition. Then there is the issue of getting it into wildlife. Rabies was easy - a viral vaccine with good humeral immunity.

Culling - the results from RBCT were flawed (interference of traps, 2001, suspending the experiment due to apparent adverse effects) but even they (and subsequent work, showed widespread culling worked. There is some doubt about the interpretation the data that I won't go into as I've not fully read up on it. I'm not convinced the current culling will work.

Badger Ecology - a wonderful animal (no sarcasm) with unfortunately a 77% increase in 10 years (Mammal survey). It eats everything and we've given it the perfect food (maize) and mild winters have reduced numbers. In Germany they are hunted and eaten and I understand the population are in good shape.

There should be no argument that badgers are the cause of much of the TB in the UK. The only debate is what to do about it. I'd see the protection removed as they are not endangered and the ecological impact of an unchallenged mess-predator is growing.

RE: Badgers and TB

Anthony Todd — Wed, 19 Apr 2017 15:18:01 GMT

And/ but the cattle are always outdoors.

RE: Badgers and TB

Neil Wheadon — Wed, 19 Apr 2017 15:16:02 GMT

New Zealand varies considerably to the UK in 2 respects

1) Possums are the endemic carriers, the government positively encourages culling. Only in the UK and Ireland do we have Meles Meles (Mr Badger). That's why Europe don't have the problem. Interesting to see where the TB funding will come from in future as we are required by EU legislation to get rid of it and receive funding to do so

2) Farming is a big part of New Zealand, the government listens. This is why with the rural vote needed the tories started the cull policy again

Neil (this is taking me back to my past) Wheadon

RE: Badgers and TB

Anthony Todd — Wed, 19 Apr 2017 13:31:01 GMT

http://www.bovinetb.info/newzealand.php

This may be of interest. We were blanket testing in the 60s using the intradermal test in the tail fold and manual assessment.

A lot about the UK and badgers too!

RE: Badgers and TB

Neil Wheadon — Wed, 19 Apr 2017 13:08:28 GMT

[quote user="Michael Woodhouse"]1. Badgers contract and can spread TB. Unlike other mammals (where it is predominately a lung disease) infected badgers pass the bacteria in their urine. They come out of their sets to urinate and contaminate the environment with the mycobacteria that survives quite well in the environment.[/quote]

TB doesn't kill Badgers quickly, they are super excreters and roam up to 3km at night

With deer they have a very narrow geographical area, and TB kills them quite quickly

[quote user="Michael Woodhouse"]Culling (when done properly and effectively) vastly reduces breakdowns, but when done badly it disrupts badger social groups which causes the perturbation effect. For culling to work large numbers of infected badgers need to be killed in infected areas. [/quote]

Yes, that's why gassing is effective

[quote user="Michael Woodhouse"]The intra-dermal skin test is not perfect but good enough to eradicate the disease when there is no wildlife reservoir of infection. [/quote]

It has a 99.9% Specificity, 80% (I can't recall the exact figure) sensitivity. That means if done properly that if you get a lump it's TB. The problem is in cases where a cow is riddled with TB and the immune system is so worn out it can't be bothered to create a reaction, the so called anergic case. This is why you will often get a slaughter house case shortly after a couple of clear tests that starts the whole testing cycle of again

[quote user="Michael Woodhouse"]Gamma interferon helps remove animals infected but not reacting to the skin test, but throws up too many false positives to make it a useful herd screening test[/quote]

Strictly speaking these aren't false positives. TB has to be active in the cow to react to the test, it's that sensitive. The thing is that just because you catch TB doesn't mean you're going to develope it. Gamma testing was used in buffer areas (on the edge of annual parishes) and 4 year testing areas. It wasn't that uncommon to lose 1/3 - 1/2 of the herd, awful, how do you justify that to a business where the reservoir infection is left alone?

[quote user="Michael Woodhouse"]I also think 4 years is too long between tests in 'free' areas.[/quote]

Agreed, however I think this has changed? What was done was smoothing. In this case a few farms in a parish was tested annually, rather than on block every 4 years. In effect these cases were deemed as sentinels

[quote user="Michael Woodhouse"]Who knows what happens to TB reactor cattle?[/quote]

You'll need to explain that one Michael

Neil

RE: Badgers and TB

Neil Wheadon — Wed, 19 Apr 2017 12:54:50 GMT

[quote user="Michael Woodhouse"]

Have a look at the graphs and data about 3/4 down the page

http://www.bovinetb.info/ireland.php

[/quote]

You're referring to the Irish study, where they actively cull badgers

There is also an article in the Irish Vet Journal (from memory) in Western Ireland where a pro-active cull reduced TB

Add the Thornbury ring

and... As a farmer said to me, if you had a business, say a small animal practice and someone came in every 60 days and smashed the place up, what would you do?

Take a farm with over a 1000 cattle. If the environment is contaminated, what is the chance of getting 2 clear tests in a row, especially when read at severe interpretation? Smaller herds get of restriction faster, simple statistics.

Neil

RE: Badgers and TB

Michael Woodhouse — Wed, 19 Apr 2017 09:50:23 GMT

Have a look at the graphs and data about 3/4 down the page

http://www.bovinetb.info/ireland.php

Year	Number of cattle in the Irish Republic	% of cattle culled in Northern Ireland	% of cattle culled in the Irish Republic	% difference	The number of cattle saved
2008	6150163	0.517	0.486	0.03	1906
2009	6025656	0.513	0.395	0.12	7078
2010	5751564	0.399	0.351	0.05	2724
2011	5819281	0.512	0.318	0.19	11246
2012	6145469	0.671	0.301	0.37	22731

Average number of cattle saved each year = (1906+7078+2724+11246+22731)/5 = 9137