Early lambing flocks in NI have seen a sharp rise in abortions and malformations due to Schmallenberg, reports from local vets and farmers indicate.

The virus is spread by midges and the most susceptible period for pregnant ewes to become infected is around 25 to 50 days in-lamb.

Schmallenberg also affects cattle, with the key stage of pregnancy for picking up infection being two to six months in-calf.

Early lambing flocks and spring calving herds are particularly vulnerable, as the susceptible gestation periods coincide with peak midge activity in late summer and early autumn.

A key concern is that the mild autumn in 2024 may have led to a prolonged period of midge activity and virus spread, meaning more flocks and herds could be impacted this year.

“It is colossal this year so far. We can only wait and see how long it goes on for. It all depends on where the infected midges were and how long they were active,” said one local vet.

Schmallenberg was first diagnosed in NI by the Agri Food and Biosciences Institute (AFBI) in October 2012.

AFBI states that there was “a significant peak” in cases in both 2017 and 2018, although the virus had been “largely absent” in NI since 2019.

The first case in NI in recent times was found in a two-month-old calf with brain abnormalities in October 2024. More cases have been diagnosed by AFBI since then.

Schmallenberg has been on the rise in Britain since late 2023 and incidence of the disease also increased in the Republic of Ireland in 2024.