Actions to limit Bluetongue

Livestock keepers should take action given the increased risk of Bluetongue impacting their farms in 2026 following the detection of Bluetongue Virus-3 (BTV-3).

Particularly the period from April to November, when biting midges are most active, deserves heightened vigilance and preparedness.

Infected Culicoides midges not only act as a means of transport for the virus, but are also a biological vector, meaning the virus replicates and multiplies inside the midge. For this to take place, sustained temperatures above 12°C are needed, hence the current lower risk of BTV-3 spreading widely. However, Irish summers now regularly exceed this threshold, increasing the likelihood of virus amplification in even a single infected midge.

Recognising the increased risk, BTV-3 vaccines have been authorised to use in cattle and sheep in 2026. The same vaccines have been used successfully in UK and The Netherlands to limit the impact of BTV-3 on livestock. These vaccines do not eliminate the spread of the virus but mitigate the health impacts of the disease on cattle and sheep. Farmers looking to vaccinate livestock should discuss this with their Veterinary Practitioner and aim to have this completed before peak midge season later this Spring.

Because vaccination doesn’t eliminate the impact or spread of BTV-3 a combined approach of vaccination plus biosecurity remains essential to control this disease:

• Farmers purchasing animals during the higher-risk April–November period are advised to request pre-movement PCR testing and implement short-term isolation on arrival.
• While midges cannot be eradicated from the Irish countryside, farmers can take meaningful steps to reduce contact between livestock and biting insects:
  • House animals at dusk, when midge activity peaks.
  • Improve airflow in sheds and handling areas.
  • Reduce wet, manure-rich zones around buildings and yards, these are ideal breeding habitats for midges.
  • Consider pyrethroid-based pour-ons in consultation with your Veterinary Practitioner. These can reduce biting pressure but should not be relied upon as the sole control measure.

Bluetongue is a notifiable disease, and early detection is essential for protecting the national herd. Key signs include fever, reduced appetite, milk drop, drooling, swollen lips or tongue, lameness, nasal or ocular discharge, and abortions. Sheep tend to be more severely affected than cattle and observations from the UK would indicate that the current BTV-3 strain is causing less prominent signs compared to the early days of the outbreak in The Netherlands. Any suspicion must be reported immediately to your local Regional Veterinary Office. For more details, visit gov.ie – Bluetongue Virus.