Following the AHVLA’s confirmation of the discovery of Schmallenberg virus (SBV) on four sheep farms in Norfolk, Suffolk and East Sussex, the British Veterinary Association (BVA) has renewed its call for heightened vigilance.

Scientists believe that the virus is vector-borne, even though they have not ruled out other routes of transmission. At the present moment, the clinical signs observed together with meteorological risk models, indicate that the four farms were affected either in summer or autumn 2011. Hereditary defects are now being seen at lambing time.

Imported animals from affected areas in northern Europe are also considered to be at potential risk, with their UK destinations being tagged.

The hereditary deformities and nervous defects are visible in newborn lambs, (goat) kids and calves. The clinical signs in affected cattle are similar to ‘winter dysentery‘ and consist of fever (pyrexia), milk drop, and diarrhea. Farmers are advised to monitor their herds and flocks for clusters of these signs and report to their veterinary surgeon.

Vets should remain alert and report any suspicious clinical signs of animals on their client’s farms to AHVLA, SAC or the local DARD divisional veterinary office for further investigation.

AHVLA, SAC and DARD have declared that they are willing to examine potential cases at no extra cost for the SBV tests they undertake, however their approaches vary between countries. For instance, in England, Wales and Northern Ireland AHVLA and AFBI perform free-of-charge SBV-only testing to determine whether or not the animal is affected, but they do charge for the standard subsidized investigation charge for any additional diagnostic work. In Scotland, any carcasses submitted for post mortems are examined at the standard fee, but all examinations necessary according to the VIO for investigation are included in the fee. SAC does not charge an additional fee for SBV testing.

Commenting, Carl Padgett, President of the BVA, said:

“The confirmation of Schmallenberg virus in sheep flocks in England is a reminder to vets and farmers across the UK to step up vigilance amongst ruminants. The BVA would encourage vets to speak to their local AHVLA, SAC or DARD team to discuss any suspect cases and consider submitting specimens for further investigation. We understand that in confirmed cases clinical signs occur in clusters and vets should ensure they know what to look for in both adult and perinatal ruminants.

While the cases in the south east of England suggest the virus is vector-borne, other potential routes of transmission are still being considered. Although the risk of zoonosis is believed to be very low, it has not been ruled out and a sensible precautionary approach should be taken by those handling infected animals and specimens.”

Written by Petra Rattue