The National Sheep Association (NSA) is calling for the urgent introduction of a Schmallenberg (SBV) vaccine following the discovery of the virus in Welsh cattle.
SBV antibodies have been discovered in three cows and one calf on farms in Ceredigion, west Wales.
The animals’ history suggests they were infected by the virus while on the holding up to a year ago.
But despite significant progress, a vaccine is not ready for the breeding season, putting more animals at risk of infection.
Joanne Pugh, NSA senior communications officer, said: “This new case proves that point and shows how important it is for DEFRA and others to continue to look at vaccination options.
“In the meantime, farmers must be vigilant to signs of infection, as it is only by seeing different cases that we can lean more.”
Ms Pugh added that it was disappointing to hear that Schmallenberg had been circulating in west Wales. The NSA thought it had not spread that far at this stage.
“This new case proves that point and shows how important it is for DEFRA and others to continue to look at vaccination options.”
“We understand that investigations are going to be carried out at the farm by AHVLA and Welsh government, and it is vital that these are carried out quickly and thoroughly, so we add to our limited understanding of the virus.”
However, NFU Cymru said the presence of the virus in Wales was not unexpected, since it has already been detected in 275 premises in England.
As of July this year, there were 275 UK farms reporting positive for SBV. Of these, 53 were in cattle, 219 in sheep and three in both.
But Ed Bailey, NFU Cymru president, said the timing of the discovery was “very worrying” for Welsh farmers as it coincided with autumn breeding.
The discovery of SBV on the Welsh farm and the bovine TB vaccination programme will be discussed by chief veterinary officer for Wales Christianne Glossop during the Farmers’ Union of Wales’ Flintshire county branch annual general meeting at Rhosesmor Village Hall next Wednesday, 3 October at 7.30pm.