The Bluetongue map of Europe continues to change every month even at this time of the year as more strains are detected. The ones that have been found this year are1,2,4,6,8,9,16 and the Toggenburg Orbivirus isolated from goats in Switzerland which will probably be classified as the 25^th strain. In the middle of November imported sheep in both Gloucester and Dorset blood tested positive for the BT8 virus. Also it has been found that five imported cattle on a farm near Blackpool have tested positive for BTV1 so we have joined most of France and much of Spain in having two different strains of the virus detected in our farm stock. DEFRA have reacted quickly to this latest discovery and they have destroyed all of the animals involved as well as the rest of the consignment as they were thought to be dangerous contacts. From what I understand it is very unlikely, if not impossible for the virus to spread at this time of the year, if the animals were recently infected with BTV1 they should develop a full natural immunity long before the end of this Vector Free Period so they are no threat to other animals. It does give a strong message about the risk of loosing animals that are imported from the active Bluetongue areas of Europe. If it is not possible to stop these imports there should at least be a way of isolating them here until there are clear test results.

Sheep Abortion

I was interested to hear what David Buxton had to say at the sheep meeting at the market the other evening. Essentially it is still enzootic and toxoplasma abortion that will cause the most problems. Enzootic often comes when replacements are brought in the autumn. There is no way of knowing if the new ewes have been exposed to the infection last year, if they have whatever you do they will loose their lambs next year before they become fully immune. There was some discussion about using antibiotics after one hundred and ten days of pregnancy to limit the losses. It was emphasised that, if you get the timing right is does save lambs, the infection is a bacterial disease that grows on the cotyledons, the antibiotic slows the progress of the infection, but it will not stop the ewe passing contaminated secretions in the lambing pens and the resultant off spring will not reach their full growth potential as they did not get a full blood supply before birth.

Toxoplasma

Young cats are very much involved in the toxoplasma story. This is a protozoan disease that cats pick up from infected mice. Well fed cats will build up an immunity to the infection, after two years of age they secrete few or no oocysts in their faeces. It is difficult to stop cats contaminating the fodder, hard food or fields that the pregnant ewes have access to. Toxoplasma commonly affects just one of the foetuses or will cause foetal resorbtion from an early stage so the ewe will be scanned as empty. It would seem that Deccox has little effect on the infection, but it does improve the appetite of the ewe which might help.

Vaccination

The meeting was partly sponsored by Intervet so as you would expect there was much talk about using Enzoovac and Toxovac vaccines. The main problem with these is the timing as they are live vaccines the must be given at least one months before the rams start to work. It is not always possible to comply with this. Sheep aborting is a world wide problem. They have reports that in New Zealand even on remote isolated farms they still have problems with toxoplasma as the cats somehow find the places where pregnant sheep are fed.

Controlling the Cats

It would seem to me that the key to this is not to have young cats on the farm. It is better to keep one entire tom cat and to neuter all of the rest. If you can keep a small stable colony of cats they can hunt mice all day and not pose a risk to your sheep once they have reached their second year. It is no good trying to get rid of all of the cats as new younger ones will turn up from somewhere. Shropshire Cat Rescue will help to catch and neuter cat colonies on farms. We use a catch trap which you bait with food that will hold the cat until you can bring them to the Surgery. We can deal with both nervous and aggressive cats in this way.  It is the first step to stop your ewes aborting.

Horse Passports

DEFRA have issued a consultation document about how they can implement the new European regulations for identifying horses. Essentially from July next year it will be a requirement that all horses in England must be issued with a passport within six months of birth. As well as the silhouette a microchip will be inserted in the neck and recorded on the form. This is partly to prevent horses having more than one passport as the microchip number will be recorded on the National Equine Database

Christmas

Everyone at the Surgery would like to wish you a Happy Christmas and a Peaceful New Year.

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