Bluetongue: how to spot and report the disease

How bluetongue is spread

Bluetongue virus is mostly spread by certain species of biting midges (culicoides species), many of which can be found throughout Great Britain.

Midges are infected with the virus when they bite an infected animal, and the virus spreads when the infected midge bites an uninfected susceptible animal. Once a midge has picked up the bluetongue virus it will be a carrier for the rest of its life.

The time of year (midges are mainly active between April to November), meteorological conditions (temperature, wind speed and direction and rain), topography and the proximity and density of neighbouring farms with susceptible animals, are significant factors in any potential incursion and on how quickly, and how far midges can spread the disease.

Bluetongue virus can also be spread through biological products, such as blood, germinal products (semen or embryos), or the movement of infected animals.

Infected pregnant animals can, under certain circumstances, transmit the virus to their unborn offspring. Once born, the infected offspring could act as a source of bluetongue virus.

The severity of the infection depends upon the serotype of the virus and may also be affected by strain. New serotypes continue to be identified, but only serotypes 1-24 are notifiable.

Practice good hygiene when vaccinating animals

Bluetongue can also be transmitted through dirty needles.

Animal keepers and vets should follow good practice when treating and vaccinating animals at risk of being infected with bluetongue.