Responsible sourcing, vigilance, and recognition that vaccine developments will not be a silver bullet are the key messages for Scotland’s livestock farmers as Bluetongue virus cases in England and Europe grow.
NFU Scotland’s Animal Health and Welfare Policy Manager Penny Middleton writes: “Bluetongue Virus 3 (BTV3) has continued to spread within the Netherlands, Belgium, Germany, France, Luxembourg, Denmark and Switzerland this summer and there was always an expectation we would see incursions on the east and south coasts of England because of infected midges being blown across from the continent.
“Over the past two weeks we have seen increasing reports of infection in Norfolk and Suffolk and now in Yorkshire and it is now clear we have active disease circulating within the midge populations in these areas. Officials detected all the cases through farmers reporting clinical signs in affected animals, confirmed by testing.
“BTV3 is a relatively new strain of Bluetongue and not too much is known regarding how the virus behaves compared with other strains. There are currently three vaccines newly developed and yet to receive full marketing authorisations.
“Some Member States have been allowing their use under emergency authorisation and Defra’s Secretary of State has now also allowed the use of three unauthorised BTV-3 vaccines within the United Kingdom, subject to licence.
“Licences will allow use either through geographically targeted general licences, initially in high-risk counties, as part of a phased approach or by application for specific licences through APHA. Wider licencing roll out will be subject to Risk Assessment.
“Unlike other BTV vaccines, the currently available BTV-3 vaccines are suppressive, not preventative. This means that they will not prevent your animals from being infected or becoming infectious, although they may reduce the clinical signs experienced. For this reason, all movement controls and trade restrictions in place will still apply to vaccinated animals.
“Epidemiologists believe Scotland may be on the edge of geographic limits for the virus to persist and spread, but this will be very weather dependent and a warm spell at this time could allow infection to spread and reach Scotland.
“As a midge borne virus, that means disease can spread on the wind, but the real risk of spread over distances is through the movements of infected animals.
“Control zones are in place in England preventing animal movements out of the high-risk zones, but disease could be spreading, undetected, out from those zones.
“The advice to keepers in Scotland is to keep disease out by careful sourcing of animals and rapid detection and reporting of any suspicion of disease in the hope we can stop disease before it starts to circulate.
“We urge keepers to avoid moving cattle and sheep from high-risk areas around the East and South coast, including inland counties around these zones.
“Please remain vigilant and report any suspicion of clinical signs in your animals including a sudden drop in milk production in dairy cows, fever, lesions, redness of the mouth, eyes, nose or skin above the hoof, excessive salivation and nasal discharge. Clinical symptoms tend to be less severe in cattle than in sheep and some producers on the continent have seen high levels of mortality, although severity does vary.
“Responsible sourcing and vigilance will be the keys to Scotland’s preparedness and response to the threat posed by BTV3.”