A veterinarian is confirming that Schmallenberg disease has significantly impacted the performance of early lambing flocks in Northern Ireland over recent weeks.
Fane Valley veterinary advisor, Charlotte Martin, spoke at a recent lamb information evening held in Ballycastle, Co. Antrim.
Affected flock owners are reporting large numbers of lamb losses, with up to 40% of ewes impacted by the virus in some cases..
Martin said; “Schmallenberg is spread by biting midges, which have higher activity levels during the summer and autumn period. They are also responsible for the spread of bluetongue disease.”
“Schmallenberg infections lead to the development of deformed lambs, the vast majority of which do not survive birth.
“Affected ewes can sometime abort lambs at time of infection.”
According to the veterinarian, Schmallenberg is not a notifiable disease, but bluetongue is.
“The impact of Schmallenberg on the foetus takes place during the first 25 to 50 days of gestation. If a midge bites a ewe during mid lactation, she is unlikely to have a deformed foetus,” Martin added.
“Prevention is the best way of avoiding Schmallenberg becoming a problem in the first place.”
Schmallenberg spread
It has been shown that winds at strengths above 3m/sec will prevent midges from biting potential hosts. However, they do travel in the wind.
This phenomenon has resulted in infected midges being brought across to the island of Ireland in the first place.
“This is why coastal areas in this part of the world are more likely to be Schmallenberg-impacted,” Martin explained,
“No insecticide claims to kill midges fast enough to prevent a single bite from a midge. That said, these products can deliver some form of protection against Schmallenberg. So using pour-on products and getting ewes dipped is important.”
She explained that the other option is to plan to lamb later. There was a vaccine for the disease on the market a number of years ago, however it was not attractive to farmers.
“It is no longer available so the reality is that vaccinating against Schmallenberg is not an option at the present time,” the vet said.
“Ewes will develop an immune response to Schmallenberg but the length of time this response lasts is unknown.
“Immunity to Schmallenberg could last for six months or it could be longer. At the present time we do not know the answer to this question.
”But certainly, if a ewe contracted the disease this year, I wouldn’t count on her being immune three years from now,” she concluded.
