What is Maedi Visna? It is a nasty viral disease rife in many commercial sheep flocks.
So, what is this to do with my Ouessants you may wonder? Well, any sheep can get it and you may not even know your sheep have it until symptoms start to appear.
It’s very similar to CAE (Caprine Encephalitis Arthritis) in goats which is also a rather nasty disease.
Now there are three ways of looking at it:
- Don’t test – most flocks of Ouessants in Britain are not tested.
- Have a test done to make sure your sheep are negative, which may be a good idea if selling any sheep to buyers who already have CAE tested goats, because more and more people are testing their goats.
- Become MV accredited, which is the more expensive option. This means any new animals you bring in, have to be isolated from the accredited flock until they have passed two blood tests. So pre-planning is necessary.
I have always had CAE tested goats and later when I had pedigree Zwartbles sheep, they were also MV Accredited. Having had several people ask me if I was going to accredit my Ouessants I immediately thought yes! So I contacted my vet and arranged it all.
So what actually happens? The sheep must all be identified with their tags and these must be written down on a handy piece of paper, which is a lot easier than trying to write straight on the phials of blood! The sheep are penned and then one by one, a blood sample is taken and their
UK number written on it.
Once finished, the vet sends all the blood samples along with relevant paperwork to the laboratories dealing with this, which are at the Scottish agricultural college (SAC) in Edinburgh. The results return within about three weeks.
The test is then repeated six months later and so long as the second test is also negative the flock is pronounced Maedi Visna free and becomes accredited.
These sheep are not allowed to mix with any non-accredited sheep and must always be at least 3 metres from non-accredited sheep. They are also not allowed to walk on ground non-accredited sheep have been on for several days.
I realise this is not for everyone but thought I would share with you at least one of the diseases sheep can have, and how to make sure your sheep are free of this disease.
|What is it? A viral disease that can be transmitted via milk, colostrum, faeces and respiratory secretions. Close contact during housing can increase the risk of disease spread.
Symptoms The name is made from two Icelandic words that mean pneumonia and wasting – the main clinical signs.
Symptoms can also include mastitis. Maedi visna will reduce conception and milk yields, potentially increase premature births and lamb mortality, and reduce growth rates.
Impact on flock The disease is highly contagious and fatal, so will lead to increased mortality rates.
Infected flocks are likely to see increased culling due to chronic weight loss and poor fertility. New UK data has shown an approximate 7.3% reduction in milk yield from infected ewes.
How to find out if you have it on farm Maedi visna can be identified through blood testing or milk sample testing.
How to prevent it There is no vaccine for the disease. You can reduce the risk of infecting your flock by purchasing breeding stock only from Maedi visna-accredited flocks.
How to control/treat it There is no treatment for Maedi visna.
Author: Val Grainger