NB: Current outbreak is in Northern Europe

Bluetongue is a notifiable disease of livestock in the UK, and as such if it is suspected it must be reported. This can be done by calling the Defra Rural Services Helpline on 03000 200 301. In Wales, contact 0300 303 8268. In Scotland, contact your local Field Services Office. It does not affect humans or food safety, but outbreaks can result in prolonged animal movement and trading restrictions.

Bluetongue was first described in South Africa but has been a recognised disease in most countries in the tropics and sub tropics for some time. Since 1999 there have been significant outbreaks in Greece, Italy, France, the Balearic Islands and for the past few years, cases have been springing up in northern European countries such as the Netherlands, Germany and Belgium.

Update 11 November 2023

Following routine bluetongue surveillance, a single cow has tested positive for bluetongue serotype 3 on a premises near Canterbury, Kent. A 10 km temporary control zone has been declared around the premises where the animal was kept. Movement restrictions apply to cattle, sheep and other ruminants.

Bluetongue affects sheep, cattle, other ruminants such as goats and camelids such as llamas.

Strains of bluetongue virus are currently circulating widely throughout Europe, and it is possible that bluetongue could spread into the UK if infected midges are carried by the wind to England. The exact level of risk depends on the proximity of disease in Europe and the weather conditions however bluetongue could also spread into the UK if infected animals, or germinal products, are imported from countries where bluetongue is circulating. Although the impact varies between strains (serotypes) and at present 24 distinct serotypes have been identified, Bluetongue can have significant economic impacts in terms of on farm losses due to death, sickness, reduced productivity and losses

The virus cannot be transmitted between animals - only via the bite of a Culicoide midge. However, the BVA concede that mechanical transmission is possible between herds and flocks, using contaminated surgical equipment or hypodermic needles. Animal keepers and vets should follow good practice when treating and vaccinating animals at risk of being infected with bluetongue.

Peak populations of vector Culicoides occur in late summer and autumn - resulting in a higher level of infection at that time. Once a midge has picked up the BTV virus it will be a carrier for the rest of its life. The midge season in the UK is usually April to November. The weather, especially temperature and wind direction, affects how quickly, and how far midges can spread the disease.

How to spot the disease

Clinical signs can vary by species, although symptoms are generally more severe in sheep. Cattle can be infected more frequently, but often show no symptoms at all and this is often the case for goats too.

If you keep livestock, you must continue to keep a close watch for, and report, any signs of bluetongue disease in your animals.

Signs of bluetongue in sheep include:

·        Eye and nasal discharges

·        Drooling due to ulceration of the mouth

·        High body temperature

·        Swelling of mouth, head, neck

·        Lameness

·        Haemorrhages

·        Inflammation of the junction of the skin and horn of foot - the coronary band

·        Respiratory problems

·        A blue tongue is rarely a clinical sign.

·        Deaths of sheep in a flock may reach 70%. Animals that survive may lose condition resulting in

·        reduction in meat and wool production

·        red skin as a result of blood collecting beneath the surface

In cattle
Cattle are the main carriers of bluetongue. It is possible that cattle will show no clinical signs but signs could include:

 

  •         lethargy
  •        crusty erosions around the nostrils and muzzle
  •        redness of the mouth, eyes, nose
  •        reddening of the skin above the hoof
  •       nasal discharge
  •        reddening and erosions on the teats
  •       elevated temperature
  •        milk drop
  •         not eating
  •        Swelling of the head, neck
  •       Conjunctivitis
  •         Swelling in and ulceration of the mouth
  •        Swollen teats
  •        Drooling

In cattle the disease cannot be diagnosed on clinical grounds and requires laboratory testing to confirm. Most adult animals show only mild clinical signs, or show no signs of disease at all.

In calves

Calves can become infected with bluetongue (BTV-8) before birth, if the mother is infected while pregnant. Signs of infection include:

·        calves born small, weak, deformed or blind

·        death of calves within a few days of birth

·        abortions

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

Preventing and controlling bluetongue

You can help to prevent the disease by:

·        vaccinating your cattle and sheep against bluetongue, in particular the BTV-4 and BTV-8 strains

·        having good biosecurity practices in place on your holding

What happens if bluetongue is suspected? 

·        If bluetongue is confirmed APHA will control the outbreak by following the contingency plan for notifiable diseases which can be found here and the bluetongue control strategy.

·        If there is an outbreak, then APHA will place movement restrictions in zones around the affected premises.

Vaccinating your animals

Vaccination is the best way to protect animals from the Bluetongue virus. You should discuss with your vet whether vaccination would benefit your business.

You will need to get a general licence to vaccinate animals if they’re outside a restricted zone for bluetongue.

It can take up to 6 weeks for your animals to be fully immune as your animals must have 2 injections of the vaccine, 3 weeks apart.

Vets can apply to the Veterinary Medicines Directorate for a Special Import Certificate (SIC).

The certificate allows keepers to import safe and effective bluetongue vaccine directly from the EU to vaccinate their stock. 

To find out more

https://nadis.org.uk/disease-a-z/cattle/bluetongue-in-cattle-and-sheep/

Bluetongue: how to spot and report the disease - GOV.UK (www.gov.uk)

Photo Credit : Beth Driscoll