Epizootic haemorrhagic disease virus (EHDV)

Epizootic haemorrhagic disease virus (EHDV) mainly infects deer, but sheep and cattle can also be infected. It belongs to the family Reoviridae, genus Orbivirus, and 8 or more serotypes have been found. EHDV has a double layered capsid which encases 10 segments of double stranded RNA.

  • Epizootic haemorrhagic disease is a notifiable disease and should be reported.
    Please see the Defra website for advice on how to spot and report the disease.

Associated diseases:

EHDV causes epizootic haemorrhagic disease (EHD) which doesn’t usually kill livestock, but it has become an emerging disease in cattle, and was added to the World Organisation of Animal Health list of notifiable diseases in May 2008. Livestock owners need to be aware of it due to the lower productivity rates of infected animals such as cattle weight loss and lameness.

Clinical signs:

  • Loss of appetite
  • Fear of humans lost
  • Extensive haemorrhages
  • Weakness
  • Excessive salivation
  • Rapid pulse and respiratory rate
  • Fever
  • Blue tongue from lack of oxygenated blood
  • Breaking of hooves caused by growth interruptions
  • Diarrhoea
  • Unconciousness
  • Death

Disease transmission:

EHD is not transmitted from animal to animal, but by biological vectors such as the biting midge, Culicoides variipennis and other biting gnats and mosquitos. Outbreaks typically occur in late summer to early autumn and stop with the onset of frost because of the die-off of biological vectors.

Disease prevalence:

The disease can be found in North America, Australia, Asia, and Africa, occurring most frequently in southern United States. In south US the disease is frequent and mild, whereas in the north the disease is sporadic, severe, and capable of high mortality.

Research papers

Rajko-Nenow P, Howson E L A, Clark D, Hilton N, Ambagala A, Svitek N, Flannery J, Batten C (2021)

Viruses 13 (11) , 2187
Publisher’s version: https://doi.org/10.3390/v13112187
Brown-Joseph T, Rajko-Nenow P, Hicks H, Sahadeo N, Harrup L E, Carrington C V, Batten C, Oura C A L (2019)

Veterinary Microbiology 229
Gordon S J G, Bolwell C, Rogers C W, Musuka G, Kelly P, Guthrie A, Mellor P S, Hamblin C (2017)

Onderstepoort Journal of Veterinary Research 84 (1) , a1505
Sanders C J, Harrup L E, Tugwell L A, Brugman V A, England M, Carpenter S (2017)

Journal of Applied Ecology 54 (5) , 1429-1439


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