MV - Thin Ewe Testing Package

Ewe with sucking lamb

Is your flock infected? Low cost test package to identify flock infection


Maedi visna (MV) poses a significant challenge to the productivity and profitability of sheep flocks.


What is MV and what are its effects?
MV is a viral condition that causes loss of condition and also pneumonia, mastitis and arthritis. In some cases it can also affect the nervous system causing ewes to drag a leg or become paralysed. Sheep in thin body condition have reduced fertility, smaller, weaker lambs are born and they grow less well because of lower milk production. A study carried out on one outbreak in a commercial flock in Scotland found that lamb mortality was 36% and there was an adult mortality rate of 14%. The level of infection in the flock had reached 68% in four years. At this stage the only viable option was to cull the entire flock. Another commercial flock owner has estimated that MV has cost him £30-50,000 through a 20%-40% reduction in productivity.


The disease can exist in a flock for a number of years before clinical signs are seen. This is because a slow virus is responsible and the incubation period is long. This means, however, that infection has often spread significantly before it has been detected and control can then be difficult. Clinical signs are often not seen until around 50% of the flock is infected and at that stage eradication is very difficult, if not impossible.


What can be done about it?
There is no cure and no vaccine is available for control. Infection is lifelong. Infected sheep may die prematurely or need to be replaced early. They slowly waste away and are more susceptible to Pasteurella pneumonia. It is therefore essential to try and keep infection out of a flock. Ideally replacement stock should be sourced from MV accredited flocks but if that is not possible the sheep can be blood sampled on arrival before they enter the flock. Ideally contact with other flocks should be avoided.


If infection is identified at an early stage steps can be taken to either eradicate it or to reduce its effects in the long term. We have a tried and tested eradication procedure, which is available through the Premium Sheep & Goat Health Schemes at reduced test cost rates.


How do I know if infection is present in my flock?
There are many conditions that can cause ill thrift in sheep flocks, such as liver fluke, worms, trace element deficiencies, Johne’s disease, OPA/Jaagsiekte and MV. It is important to know which ones are present so that they can be tackled appropriately.


We are offering a low cost package which will help identify if MV is present in your flock. By selectively targeting the sheep that are likely to be infected it increases the likelihood of detecting infection if it is present. Twelve thinner or older sheep should be blood sampled and these will be tested for a total of £37 + VAT. Additional tests can also be carried out on the same blood samples such as for Johne’s disease or trace elements, for an additional cost (an additional green-topped blood sample is needed if estimation of selenium status is required).


For more information please contact the PSGHS office on 01835 822456 or why not send us an email at sghs@sac.co.uk. Information can also be found on our website www.sheepandgoathealth.co.uk

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