Following outbreaks last year in France, a recent Defra assessment shows we are again vulnerable to the bluetongue virus (BTV-8 type). Vets working on farms can help us monitor livestock health and advise farmers on vaccination.
During the European outbreak in 2007 to 2008, cases in the UK were limited to the south and east. Following voluntary vaccination by farmers, the UK was recognised as free from the disease in 2011.
This year France has reported over 230 outbreaks of the virus and restriction zones are in place. The virus appears established in the Auvergne region in Central France - around 300 miles from the Channel.
The majority of outbreaks were detected through serological surveillance. Clinical signs have only been seen in a handful of animals, mainly sheep. Even so, the disease may cause more severe clinical signs in animals as the infection progresses, as we saw in 2007 and 2008.
It's not clear whether we'll be affected at the moment. The disease has almost certainly overwintered and is likely to spread through France during the summer. The UK, particularly the south and south east of England, will be at increased risk of an outbreak.
This risk is likely to increase towards the end of summer. This is due to midge-borne spread from the continent, as they carry the disease.
What we can do
While it cannot normally be transmitted directly between animals, transmission of the virus as a result of poor biosecurity practices, such as using shared needles, is possible. It can infect all ruminants, and while it does not present implications for human health or food safety, it can lead to serious financial consequences in terms of movement controls and loss of productivity.
We're working to raise awareness of the virus, and vets play a key role in this. We can both give advice on vaccination to our clients and train keepers on the signs of the disease.
In 2007-2008 a vaccine was developed with Defra support. Effective vaccines remain in commercial production and are licenced for use in the UK. Farmers who want to reduce the risk of losses from the disease may choose to vaccinate their stock.
It's here vets have a huge role to play: we can help farmers prepare by discussing whether vaccination would benefit their business.
Animals can be vaccinated at any time. Defra worked closely with industry to make the vaccine available this year by mid-July. We have robust disease surveillance procedures in place and continue working in partnership with the livestock industry to monitor developments on the continent and the consequent risk of spread to the UK. Vaccinating during summer will give protection before the risk of infection increases.
In 2014, the GB Bluetongue Virus Control Strategy was published. This set out control measures and policies that would be considered and deployed, should the virus be suspected or found in Britain. The biggest impact of those controls is to apply restriction zones of at least 150km from which susceptible animals are not able to move to other parts of the country. This prevents the rapid spread of disease in infected animals but the risk of slower spread through infected midges would remain.
And as with all notifiable diseases, animal keepers should remain vigilant for any signs of disease. They should report any suspicions to their vet and the Animal and Plant Health Agency (APHA) immediately.
Spotting the disease
The clinical signs of bluetongue vary between strains of the virus and species of animal infected. Although cattle may show no signs of illness, signs can include:
- nasal discharge
- swelling of the neck and head, especially around the eyes and nostrils
- conjunctivitis (red and runny eyes)
- crusting around the muco-cutaneous junctions of the mouth and naso-labial plane
- crusted and/or reddened teats and vulva
Signs of bluetongue disease in sheep can include:
- eye and nasal discharges
- drooling as a result of swelling of the tongue and/or ulcerations in the mouth
- higher than normal body temperature
- swelling of the neck and/or the face
- especially around the eyes and the muzzle
- inflammation at the junction of the skin and the horn of the foot – the coronary band. This may cause severe lameness with affected sheep being reluctant to rise.
Finally, vets and livestock keepers involved in the import and movement of susceptible species should consider risks carefully and check the health status of animals when sourcing stock, especially from other European countries. As a further precaution, all animals originating from affected countries are subject to statutory testing after arrival into the UK.
Suspect cases can be reported to APHA via the Defra Rural Services Helpline on 03000 200 301 and further information on our Bluetongue Virus Control strategy is available on GOV.UK.
Detailed information on the disease including the latest updates on risk and vaccine availability can be found on the National Farmer's Union website.
Follow Nigel on Twitter @ChiefVetUK