As the lambing season begins in Wales there are fears that farmers could be left badly out of pocket as they count the cost of the Schmallenberg virus.
The virus is spread by midges and can cause death or deformity in newborn stock. Some farmers who've been lambing early say they've already seen half their lambs killed.
Cattle farmers are also warning that Schmallenberg may have caused infertility in their cows. And with three months to go before the end of the lambing and calving seasons, the problem could get much worse. Hannah Thomas has more.
Llantrisant farmer, Tim Prichard says many farmers have lost 30 to 50 per cent of the lambs they were expecting this year due to the virus.
Dr Christianne Glossop, Wales's chief veterinary officer, says it's early days for a vaccine against Schmallenberg virus, but one is being developed.
Wales' chief veterinary officer says it is possible that some cattle were infected with the Schmallenberg virus (SBV) and therefore anticipates "calving problems later in the year as a consequence."
Dr Christianne Glossop says since the first clinical case of the disease in Wales in November last year there have been a further 11 positive cases of SBV in sheep.
Dr Glossop is encouraging farmers to be vigilant for signs of the disease and to seek swift veterinary assistance if they have any concerns.
A farmer has told ITV Wales News that 50 per cent of his lambs have died because of the Schmallenberg disease (SBV).
Tim Prichard, who has a farm in Llantrisant, Pontyclun, says he expected 180 lambs to be born this season but 60 have died already.
Mr Prichard says other farmers are experiencing the same thing with one losing all but one of his 23 lambs.
Schmallenberg is a disease that causes late abortion or birth defects in newborn cattle, sheep and goats.
In December last year the Chief Veterinary Officer Christianne Glossop said that there was evidence the infection was "across most if not all counties in Wales" and the disease had been detected in a deformed lamb.
Ms Glossop added: "It is likely that malformed lambs and calves will be born in Wales in the spring 2013 as a result of some Welsh sheep and cattle being infected with SBV around the time of mating this year."
Welsh farmers are being warned that an increased number of malformed lambs and calves may be born next spring as a result of Schmallenberg virus (SBV).
The Chief Veterinary Officer for Wales urges farmers to be vigilant for signs of SBV which was first detected in Wales in September.
Dr Christianne Glossop said:
"We now have evidence of SBV infection across most, if not all counties in Wales, and we have also recently detected our first clinical case of SBV in a deformed lamb."