Blue Tongue Control

There is still a great deal of controversy about the Blue Tongue control policy that is affecting all of us. Sheep and cattle continue to be imported from the Netherlands, and there have been further cases of imported animals testing positive, most recently in Northern Ireland and Wales. In both cases the animals involved were slaughtered, and in both cases it has been argued that at this time of the year there is no risk of the virus circulating in the general ruminant population so the protection zones have not changed.

Last Movements

It has now been announced that the vector free period that is helping us to move stock into Wales and further a field will come to an end at mid night on the fifteenth of March. If you will need to move stock out of the surveillance zone please get things organised now as it still takes the best part of a week before the blood results come through. It is not clear if any movements will be permitted after that date.

Vaccination Policy

The exact details of the vaccination policy have not yet been announced. European rules state that Blue Tongue vaccines can only be used in a Protection Zone. To get the vaccine to work effectively to stop the spread of disease in an area it has been estimated that at least eighty per cent of susceptible stock need to be fully protected. The latest indications are that the vaccine will first be available at the end of May. The chances are that not all of the 22.5 million doses will be released at the same time. Also this is a dead vaccine, sheep require a single dose and cattle need two injections four weeks apart to gain sufficient immunity for a full year. At best it will be July before there is a chance of getting sufficient animals immune to check the spread of the disease.

Possible Strategy

There are other issues. The vaccine does not have a product license yet. When it does it will only be licensed for use in sheep and cattle. It will not be possible to protect goats and deer that are both susceptible to this infection. Given the late arrival of the vaccine and the limited supplies it might be better to concentrate its use on the borders of where it is though the infection will have got to by the middle of the summer in order to try and create a buffer zone. Harsh decisions have to be made as to how the vaccine can be most effective. Little will be gained by using it in areas when there is a significant wild deer population as too many susceptible animals will be left to pass on the infection. I will let you know as soon as I have any more details about the vaccine.

The New Threat

I understand that although all eyes have been on the type 8 strain of Blue Tongue as it has spread in Northern Europe and to us last summer Spain has had similar difficulties with the type 1 strain of the disease. Scientists there have noted that the virus can now be transmitted by species of midge that are usually only found in the north of the country and are expecting a further spread of the disease this year. The concern is that the new strain could arrive here with imported stock and that our midges will be able to transmit the new infection as well.

Data Sheet Change

There has been a minor change to the data sheet of Depocillin, the penicillin injection that is commonly given to ewes at lambing time. The meat withhold time for sheep has been increased from four days to five days. This is good news as usually with holding time are extended for much longer each time a drug is re licensed.

Problems with Orbeseal

Pfizer are concerned because the teat sealant Orbeseal has been shown to cause black spots in mature cheddar cheese. They are not clear exactly why this should occur. It is thought that if any of the product gets into milk that is used for cheese making mineral oil containing bismuth sub nitrate can cause the black spotting. Pfizer are quick to point out that there are no toxins in the affected cheese it is just an undesirable cosmetic effect. Please be aware, particularly if your milk is processed into cheese that Orbeseal needs to be stripped out vigorously from all four quarters before the milk can go into the tank. There is no test to detect small amounts of the oil in milk samples so if there is any doubt leave the milk out for an extra day and let the calf have more time to get rid of the sealant.

Hydatid Disease

I have received a letter from the Welsh Assembly concerning hydatid disease in dogs. There have long been concerns about this parasite that occurs in Powys, Monmouthshire, parts of the Brecon Beacons and now south Herefordshire. In these areas eggs passed by dogs can contaminate the ground so that the infection is transmitted to grazing animals and sometimes to children. When the eggs hatch they are taken in the blood stream to various parts of the body where they grow slowly to form a cyst. These can sometimes get to a huge size before it is realised that any thing is wrong. This is a serious disease. In man the only treatment is surgery, this can be very difficult and is often debilitating depending on where the cyst has developed in the body. Dogs pick up the infection if they have had contact with infected meat, raw offal or if they have had access to sheep that have died and been left on a field or yard. Border Collies in particular are most likely to pick up and spread hydatid disease. It is possible that you may have brought infected sheep onto your farm, there is no test to detect the cysts in sheep, they can be quite small and they do little harm to the sheep.

Preventative Measures

To stop the spread of the disease always wash your hands after handling dogs or cleaning their kennels. Do not allow dogs to lick faces, particularly children’s faces as worm eggs can be transmitted when this occurs. Remove all carcasses as soon as you see them, do not allow dogs to scavenge carcasses before they have been properly disposed of. It is advisable to wash all fruit and vegetables thoroughly before eating. All dogs should be wormed with a drug that is effective against Echinococcus granulosus every twelve weeks. Worm your dogs more frequently if they could have had access to fallen stock or raw meat.

An Invitation

The people who talk to us now want to talk to you. Vets from the Veterinary Laboratory Agency in Shrewsbury are holding an evening seminar at 7.00 pm on Wednesday 30th April entitled Sudden death in dairy and beef cattle causes and control. This is a golden opportunity to hear the views of the Veterinary Surgeons at the LVA who spend their time investigating disease in farm animals. There is only limited space at the Laboratory and places will be allocated on a strictly first come first served basis. To book a place please phone the Events Unit on 01932 357234.

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