Contrary to popular belief – there is no way of distinguishing which animals, flocks or herds are resistant to the Schmallenberg virus without testing.

That was the warning from Zoetis vet Carolyn Hogan, who said that while many farmers will have seen losses from Schmallenberg last year, other flocks and herds will have escaped infection.

“Even those which didn’t escape infection may be only partially immune if only a proportion of the animals were infected. This means vaccination has an important role to play in ensuring the whole flock/herd is protected, thereby preventing future lamb and calf crop losses,” she said.

With the virus moving north with recent cases detected in Northern Ireland and South West Scotland, she advised farmers to look at the vaccine for next breeding season.

At present, vaccination using Zulvac® SBV from Zoetis, is the only sure method of protection against the Schmallenberg virus, which 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).

So typically, sheep which are bred in late summer/early autumn are the highest risk group as they will be pregnant during the months when the Culicoides midge is active. Infection during the second month of pregnancy is likely to result in stillbirths and deformities.

Likewise, cows which become infected in their third to fifth month of pregnancy (70-150 days) are most at risk, meaning those calving in late autumn/winter and early spring will have cows in their third to fifth months of pregnancy during the May to October active midge period.

While midges can remain active outside this period the risk of infection reduces dramatically.

For sheep, Zulvac® SBV is a single dose vaccine making it easier to administer as stock only have to be gathered once for vaccination. It should be administered at least 14 days prior to breeding and will give protection for six months.

In cattle, the vaccine programme is a two-dose programme, with the doses given three weeks apart. Protection in cattle lasts for 12 months.

In both sheep and cattle, the vaccine can be used in animals aged 3.5 months or over.