Company
Know where you stand
30 April 2008
Vaccination and internet access are going to be the key to controlling bluetongue this summer. The vaccine will give susceptible livestock protective immunity against the BTV8 virus, while logging on to the internet regularly will help keep up-to-date with the latest advice and information. It is also possible to sign up for free email updates from Defra (see box).
Internet-free businesses, however, can always surf at their local library, or better still keep in touch with their vet to find out the latest BTV news. Vets are not just an important source of information: the vaccine Bovilis® BTV8 from Intervet is prescription-only and most practices are setting up customer ordering systems.
All livestock holdings with susceptible animals – cattle, sheep, goats, buffalo, llamas, alpacas, deer – in both the Protection Zones (PZ) and Surveillance Zones (SZ) should by now have registered with their vet to ensure supplies as soon as vaccine becomes available. Defra’s website carries a map showing the restricted zones, licences and movement restrictions.
A 20km PZ is put immediately around an infected holding, with a further 80km of PZ, followed by an SZ of at least 50km. Within this 150km zone, there are movement restrictions on livestock, carcases, semen and embryos.
Only cattle and sheep in a designated PZ can be vaccinated. But all producers are advised to plan a vaccination control policy in case infection spreads and the PZ suddenly expands. In addition, Defra says that as more vaccine becomes available, the PZ will be modified so further vaccination can be phased in.
What to do if you have livestock and are in the Protection Zone (PZ)?
Know exactly how many livestock there are of each susceptible species and work out how you will be able to vaccinate all of them in one go. Make sure you know about any legal certification or declaration needed should animals later need to be moved outside the PZ.
Bovilis BTV8 is licensed for use in cattle and sheep and can’t be used in conjunction with any other vaccines, which means working closely with your vet to ensure accurate timing. Other vaccines should not be used for two weeks either side of Bovilis BTV8. There is a nil milk and meat withdrawal.
The vaccine comes in 20ml and 50ml bottles and has to be stored at 2oC to 8oC. Once opened, it should be used within eight hours. The vaccine can be given by a vet, farmer or trained stockman using a recommended multi-injection gun. Use it only in healthy livestock over four weeks of age – and ensure that all relevant age groups are vaccinated. To ensure that 80% of susceptible species – remember this includes goats, buffalo and wild deer – are protected, the British Veterinary Association (BVA) is encouraging farmers to vaccinate 100% of their stock.
Sheep need one 1ml subcutaneous injection, whereas cattle require two 1ml subcutaneous injections given three weeks apart. Animals gain full immunity three weeks after their last injection. Re-vaccination should take place two weeks before the next bluetongue risk period (probably early spring 2009).
What to do if you have livestock in the Surveillance Zone (SZ)?
Much is the same as for the PZ. Plus, it’s important to inspect stock regularly, particularly the nose and mouth areas and the coronary band (where the skin meets the hoof), for symptoms of BTV8. And be aware of how the disease is progressing in the PZ by keeping in touch with your vet and Defra’s website. Vaccine availability and how the disease spreads will dictate how soon you will gain access to the vaccine.
According to Defra, livestock owners can apply to move livestock out of the SZ onto land within 8km of the zone, thus expanding the zone. Contact your local Animal Health Divisional Office for more information.
Whilst waiting for the vaccine to become available, look at how you can control the vector, the Culicoides midge. Butox® SWISH is the only pour-on treatment with proven efficacy against midges. It needs to be used every four weeks to help protect cattle against midges. In addition to killing midges, removing or limiting their habitats makes good sense. The midge breeds in wet leaf litter, mud, tree holes, and stream banks, so removing these will help reduce the midge population and therefore risk.
Keep stock away from low-lying damp grazing, particularly at dawn and dusk and either remove or cover dung heaps and slurry pits.
Bluetongue Restricted Zone
The Welsh Assembly declared an area in south east Wales, bordering an SZ in England, as a Bluetongue Restricted Zone on 13 February. This zone has the same disease control status as an SZ in England.
FOR FURTHER INFORMATION
http://www.defra.gov.uk/animalh/diseases/notifiable/bluetongue/index.htm
http://wales.gov.uk/topics/environmentcountryside/ahw/disease/bluetongue/?lang=en