sheep in pens© Photofusion/Rex/Shutterstock

Fourteen cases of the Schmallenberg virus (SBV), which leads to deformities in lambs and calves, have been reported in Northern Ireland.

The Agri-Food and Biosciences Institute (AFBI) has confirmed 14 cases have been presented for SBV testing to date in 2018. Any reported cases of deformed offspring that meet the clinical case definition are investigated by AFBI free of charge.

See also: Six steps to making calves more resilient to disease

SBV is not a notifiable disease in Northern Ireland but the Department of Agriculture, Environment and Rural Affairs (Daera) advises farmers to contact their local vet if they suspect the presence of the disease in their cattle or sheep.

Schmallenberg symptoms

  • Adult cattle: Fever, milk drop, loss of appetite and sometimes diarrhoea
  • Adult sheep: Few, if any, signs are exhibited
  • If cattle or sheep become infected when pregnant exposure to the disease can lead to abortion or malformations in the foetus

The virus is spread by the culicoides biting midge and first entered the UK on wind flows from Europe in 2011, causing deformed lambs and calves to be born in 2012 on 220 holdings.

The Ulster Farmers’ Union (UFU) is encouraging farmers to be vigilant against the virus and president Barclay Bell said: “It is concerning that there are a growing number of reports of this virus being found in Northern Ireland. It is an awful situation for any farmer. No one wants to see Schmallenberg on their farm.”

In England, Defra executive the Animal and Plant Health Agency (Apha) has not yet reported any cases for 2018.

The key risk months

SBV is most risky for sheep that become infected in their second month of pregnancy and cattle in their third to fifth month of pregnancy (70-150 days).

Spread of infection occurs mainly when biting midges are most active between May and October. With mild winter conditions, midge activity may extend into November and early December.

Number of premises with confirmed SBV in lambs during winter 2016-17 
England 97
Wales 42
Scotland 2
Number of premises with confirmed SBV in calves during winter 2016-17 
England 65
Scotland 10
Wales 1