What is Bluetongue (BT)?

Bluetongue (BT) is a non-contagious, viral disease affecting domestic and wild

ruminants (primarily sheep and including cattle, goats, buffalo, antelope, deer, elk and camels) that is transmitted by insects, particularly biting midges of the Culicoides species.

The virus which causes BT is identified as a member of the Reoviridae family. Twenty-four (24) different serotypes have been identified and the ability of each strain to cause disease vanes considerably.

The severity of disease varies among different species with symptoms beinq most severe in sheep resulting in deaths, weight loss and disruption in wool growth. In

Highly susceptible sheep, morbidity can be as high as 100%. Mortality averages from 2-30 % but can be as high as 70%.

Cattle often have a higher infection rate than sheep and demonstration and severity of clinical signs varies depending on the strain of virus. Currently circulating BT virus in Northern Europe is epidemiologically signifi cant because of demonstration of clinical signs in cattle.

In countries where BT is endemic the impact is largely on loss of trade due to restrictions and the costs of surveillance, health testing and vaccination.

BT is a disease listed under the OIE Terrestrial Animal Health Code and must be reported to the World Organisation for Animal Health (as per the OIE Terrestrial Animal Health Code).

Source: The World Organisation for Animal Health (OIE)