Johnes control Programme.

Phase One of the Irish Johne’s Control
Programme is drawing to a close on the 31st
December 2018. During the past 15 months over
900 herdowners have registered with the Irish
Johne’s Control Programme (IJCP) in Phase One,
and by doing so demonstrated a commitment to
preventing the spread of Johne’s disease in Ireland.
While many herdowners have completed all the
programme requirements, including a VRAMP and
testing, and have benefited from the availability of
ancillary testing, a number of herdowners have yet
to carry out these activities, or have only partially
completed their Whole Herd Test.
As part of registration with the IJCP, all herd owners
undertook to carry out these activities during
Phase One, and with less than 6 weeks left in 2018,
herdowners are reminded that they should be
contacting their Approved Veterinary Practitioner
(AVP) or milk recording organisation, as appropriate,
to carry out these activities, if they have not already
done so and also check their herd records on ICBF
to ensure all test results have been uploaded.
If you have yet to carry out either a VRAMP or
Whole Herd Test and are not sure where to start
the process a handy checklist is available on the AHI
website. Click here.
Phase Two of the programme is set to start from
1st January 2019. While details of any supports to
be provided are yet to be confirmed, stakeholders
have agreed that the programme should be open
to all herdowners in Ireland and will continue to
be based on a regular VRAMP, whole herd test and
ancillary testing for herds with test positive animals.
Separate pathways have also been defined for test
positive and test negative herds.
All herdowners who have registered in Phase
One of the programme will automatically have
their registration carried forward to Phase Two.
For herdowners who register for the first time
with the programme during Phase Two, and who
subsequently identify infected animals in their
herds, in addition to any support for testing,
veterinary advice is to be made available through
a Targeted Advisory Service on Animal Health
(TASAH) visit. The purpose of the TASAH visit is to
have access to veterinary assistance in developing
a customised control programme for each infected
herd. Registration will commence for Phase Two
from early January 2019 and further information
will be available nearer that date.
In the meantime, if you think you have completed a
whole herd test but have not yet received financial
support for this activity, please check with your
AVP or milk recording organisation to confirm that
testing of all eligible animals (including males)
has been completed and results uploaded by the
testing laboratory. At that point you should contact
AHI at jd@animalhealthireland.ie to confirm that
payment of the support has been approved.
ANIMAL HEALTH IRELAND
Contributing to a profitable and sustainable farming and agri-food sector through improved animal health
NOVEMBER 2018
JOHNE’S DISEASE BULLETIN
Phase One of the IJCP is
drawing to a close
Johne's Control
AnimalHealthIreland.ie
IRISH JOHNE’S CONTROL PROGRAMME
Animal Health Ireland, 4-5 The Archways, Carrick-on-Shannon, Co. Leitrim, N41 WN27

Mooooo wrote: »

What's the accuracy of the test? Can't see how testing for it will work in high risk tb areas. Joined the first one. All cow's went clear bar one who had an inconclusive, a negative and a positive test. Older cow in good condition.
Best practice at calving is what should be the focus, however the infrastructure and man power costs can be prohibitive, obviously if a herd is bad with it there is little other choice

Mooooo is on the ball with his comments but to take them a little further…

The problems stem from the characteristics of the causal organism and its interaction with the defences of the host. We can’t change those so we may do the best with what we have. It’s a slowly progressing disease which gives it a good chance to be passed on before it kills its host. That slow onset of disease allows it to become well established in herds before it becomes obvious (it could be over 30 years from its introduction to the herd before the crisis erupts). In the meantime its malign presence is progressively increasing the number of cases of mastitis, lameness and infertility. These cause insidious financial losses but without due recognition of the true underlying cause.

Thankfully most herds aren’t infected so the outcome of testing for them will be to take measures to keep the disease out, along with measures to ensure that any low-level undetected infection isn’t passed on further to future generations.

However, it is estimated that 20-30% of Irish dairy herds are infected, mostly at the low level of about 3% of cows- but it does vary. (About 7.5% of beef herds are infected.)

If you are a dairy man, how many of your neighbours are also dairying? Were you to have 5 neighbours dairying then one could be hosting the disease. If you go out to buy 12 heifers and end up buying from 5 different herds the odds are high you will have bought in from an infected farm.

Johne’s makes understanding Mucosal Disease look easy. The main problem with it is that interpreting the testing is complex; the disease itself is easier to understand and the limitation measures needed are understandable, even if problematic to implement.

The main work-horse test is the ELISA test. It measures antibody (produced by the host in response to the presence of the microbe) in a vain attempt to protect itself. The nature of the organism means that antibody is produced later in the course of the infection than might be the case in most other infections. This means that there will be animals in infected herds infected with the disease not yet producing detectable amounts of antibody. As the disease progresses these become infectious to other animals but as they do they also become more liable to detection. This means the most infectious and dangerous animals are the ones detected. These would be the most vital to detect so the ELISA test has value.

This allows measures to be taken for the worst animals. This could be culling or breeding to beef bulls. At the very least it allows their calves to be marked for culling and their milk/colostrum not to be fed to calves or their dung to be kept off calf paddocks. (Cows with Johne’s are more likely to be sick and have their milk being fed to calves.)

The test is highly reliable when it says an animal is positive. About 1-2% of non-infected animals will show false positive readings. Unfortunate but good as tests go.

The test falls down in its detection of the infected animals where it can only identify 13% (milk)-15% (blood) of those infected. That leaves a lot of infected animals unidentified even if there’s a good chance that these won’t actually be passing on infection yet.

So we have to do what we can to work with those limitations. Thankfully the slow time scale allows for decisions to be contemplated and discussed before being implemented. High individual readings increase the chance the animal is truly infected. Repeated positive readings over several tests are informative. Two positive results looks bad for that individual but three and she should be gone quickly. The more positives there are in a herd the more likely the any identified animals will be truly infected.

Other tests can be employed to try to confirm the presence of infection. PCR is very reliable when it gives a positive result as it detects the DNA of the microbe. It is even more reliable in then extrapolating to say that the herd is infected. Faecal culture is similarly reliable with a positive result but takes a long time to give a result.

Unlike some other diseases, Mucosal Disease for instance, where ‘test and cull’ will solve the problem, this is one disease where the testing is just one tool that needs to be applied, as it is incapable of solving the problem on its own.

Despite its limitations it can rapidly make a big difference where the disease has gotten out of hand and bring it down to manageable levels. Thankfully farms where this is the case are few and most farmers will be dealing with a more abstract problem. And that is by far better than the alternative.

Measures to put in a firebreak in the transmission of Johne’s will also have a positive impact on other diseases so there is a secondary benefit that those with some calf health problems may notice.

In summary, testing and biosecurity can make this disease controllable, even if not eradicable, and our expectation of how things should work needs to be adjusted.

I think they can enter the programme but no funding has been provided for them. That's my understanding but it would be best to check. The reward for doing it is that herds may benefit from being able to state their herd categorisation when it comes to selling (pedigree herds).
The management tools that have been developed by AHI, the VRAMP and TASAH, are available to all FOC.

From the AHI info. Basically, you couldn't rule it out, but odds would be against it. You could try a faecal culture and a blood test if you're worried, it might set your mind at rest. Clinical animals usually give positive bloods.

Maybe check faeces for Crypto, Salmonella too.

Are you sure your worm doses are effective? How are the rest of the bunch?