More bluetongue strains could reach NI, says vet

Different strains of bluetongue could emerge in NI in the future, which would require vaccines for the disease to be updated, a local vet has said.

Keith Sheridan from Parkview Veterinary Clinic said the three bluetongue vaccines which are currently licenced for use in NI protect against the BTV-3 strain of the viral disease.

BTV-3 was responsible for a major outbreak of bluetongue in the Netherlands in 2023 and has been the dominant strain circulating across Europe and the UK since then.

Speaking to the mid-Tyrone lamb group on Tuesday, Sheridan said widespread uptake of BTV-3 vaccines in the Netherlands led to a “significant reduction in clinical disease”.

“They saw that for a while, then it started to creep back up again. When they investigated it, it was actually BTV-8 that was causing it,” he explained.

Only BTV-3 has been detected in NI to date, although in England there has been a small number of BTV-8 cases and one outbreak of BTV-12 has also been detected.

“Looking to the future, we could end up going from vaccines specifically for BTV-3 to a multi strain vaccine,” Sheridan suggested.

As bluetongue is spread by midges, it is recommended to vaccinate cattle and sheep now ahead of peak midge activity in the summer and autumn months.

“In our own practice, we have had big uptake of the vaccine among spring-calving dairy farmers in particular who are very concerned about reproductive failure,” Sheridan said.

“It is hard to predict what level of infection we are going to see, so you could look at vaccination as an insurance policy at the minute,” the Strabane-based vet said.