Information issued by BAS/BLS Health & Welfare
23 September 2007
BLUE TONGUE
British
livestock Farming has been hit yet again by a seriously destructive
disease,
Blue Tongue Virus (BT), which has been spreading throughout Northern Europe for
the last
year. Late last night DEFRA confirmed that a cow near Ipswich has been
found
to be infected.
Although this is not a reason to panic it is a reason to become more informed. The information below has been gathered from the DEFRA website as well as from Janet Nuttal MRCVS, who is Honorary Secretary of the British Veterinary Camelid Society (BCVS). www.defra.gov.uk/animalh/diseases/notifiable/bluetongue/index.htm
Although a single cow has tested positive for BT, this does not mean we are heading into another epidemic. DEFRA are testing others and hope that it is an isolated case.
http://www.defra.gov.uk/animalh/diseases/notifiable/pdf/bluetongue-control-strategy0807.pdf
BVCS tells us that the virus can affect all ruminants, including camelids, but that symptoms are usually seen only in sheep. Infection is spread by midges and there are 24 viral serotypes, constantly mutating,which affect different types of midge - at least 2 of the possible midge hosts already exist in the UK. The infected female midge lives for approx 3 weeks, transmitting the virus when sucking blood, mainly at dawn and dusk. She lays eggs in protected, moist areas, especially dung. The virus cannot be transmitted to the next generation of midges and when the adult midges die off over winter it is maintained in the ruminant population, mainly cattle.
In the ruminant host the first clinical signs are seen 3-5 days after the infected midge bite (see the above website for details and pictures) but the virus can persist for up to 50 days in sheep and up to 100 days in cattle. Mortality in sheep ranges from 30-70%.
Suggested Bio-Security Control:
- House animals, especially between dusk
and dawn
- Clean up manure piles
- Use insecticides on animals
- Smudge fires
- Insect killers - see www.midgeblaster.co.uk
Download the above as a PDF here