Bluetongue virus (Btv)

Bluetongue virus serotype 3 (BTV-3) was confirmed in Great Britain for the first time in November 2023 on a premises in Kent. Further cases have been found in Kent, Norfolk, and Suffolk. There is no evidence that bluetongue virus is currently circulating in midges in Great Britain. 

Latest information

For the latest updates on the Bluetongue situation in England, please visit GOV.UK. Further information and resources on the current bluetongue situation are available on the Ruminant Health and Welfare website.

Suspicion and confirmation

Contact your local Animal and Plant Health Agency (APHA) office immediately on 0300 303 8268 if you suspect Bluetongue.

APHA vets will investigate suspected cases.

Clinical signs

The following clinical signs may be present in sheep:

• ulcers or sores in the mouth and nose
• discharge from the eyes or nose and drooling from the mouth
• swelling of the lips, tongue, head, neck and coronary band (where the skin of the leg meets the horn of the foot)

Other clinical signs include:

• red skin as a result of blood collecting beneath the surface
• fever
• lameness
• breathing problems
• abortion
• death

The following clinical signs may be present in cattle:

• lethargy
• crusty erosions around the nostrils and muzzle
• redness of the mouth, eyes and nose
• reddening of the skin above the hoof
• nasal discharge
• reddening and erosions on the teats
• fatigue
• fever
• reduced milk yield
• loss of appetite
• abortion

Adult cattle may serve as a source of virus for several weeks while displaying little or no clinical signs of disease. They are often the preferred host for insect vectors.

Bluetongue in calves

Bluetongue can be transmitted to a foetus from an infected pregnant animal. This can lead to abortion, calves being born small, weak, deformed or blind, and death of calves within a few days of birth.

The BTV-8 strain of bluetongue circulating in France is likely to cause fewer clinical signs in adult cattle. But it will cause more instances of clinical problems in calves.

Livestock keepers and vets should consider bluetongue as a possible cause for calves showing these signs.

Transmission

Bluetongue virus can be 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. The virus spreads when the infected midge then 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.

Midges are most active between April to November. The weather (temperature, wind speed and direction, and rain) affects how quickly and how far midges can spread the disease.

Bluetongue virus can also be spread through the movement of infected animals, and through biological products such as:

• blood
• germinal products (semen or embryos)

including by imports from countries where Bluetongue may be circulating undetected.

There is evidence dogs and other carnivores can become infected with bluetongue virus after ingesting infected material such as aborted material or afterbirth.

However, this is a rare occurrence. Bluetongue is principally a disease which affects ruminant animals such as:

• sheep
• cattle
• goats 
• deer

and camelids such as:

• llama 
• alpaca

It is spread by midges.  It does not affect people or food safety.

Prevent your pets from eating, chewing on or playing with potentially infective material. For example: aborted material, afterbirth.

When you walk your dog, follow the Countryside Code (on Gov.UK) and Marine Codes of Conduct (on Wild Seas Wales).

Contact your vet if you have concerns about the health and welfare of your pet.

Prevention and control

You can help to prevent the disease by:

• vaccinating your animals with a suitable authorised vaccine
• responsibly source livestock
• practicing good biosecurity on your premises
• remaining vigilant

Keepers considering importing animals or biological products from BTV affected countries should consult their vet on the risks of doing so. This should be done before deciding to import. Imported animals that test positive for Bluetongue may be culled or be returned to the country of origin. Further information on import requirements is available on GOV.UK.