1. What is Bluetongue?

Bluetongue is a viral disease affecting ruminant animals, including cattle, sheep, goats and deer. It is caused by the Bluetongue virus (BTV) and is spread mainly by biting midges (Culicoides species).

  • It does not affect humans.

  • Milk and meat remain safe to consume.

Several virus strains (serotypes) exist. In Ireland the current concern is Bluetongue virus serotype 3 (BTV-3).

2. Current Situation in Ireland (2026)

  • Ireland confirmed its first case of BTV-3 in January 2026 in County Wexford.

  • Additional cases have since been detected in multiple cattle herds in southern and eastern regions.

  • Some infected animals show no clinical signs, making surveillance important.

  • Vaccination of cattle and sheep is permitted in Ireland from 2026 to reduce disease impact.

Bluetongue surveillance is ongoing nationally to monitor spread and guide vaccination decisions.

3. How Bluetongue Spreads

Bluetongue is not spread directly from animal to animal. It spreads mainly through the bite of infected midges.

Main transmission routes

  • Biting Culicoides midges

  • Movement of infected animals

  • Wind-borne infected midges from other countries or regions

Midged activity is highest during warm months (April–November), so disease risk increases during summer and autumn.

4. Animals Affected

Bluetongue affects ruminant species, especially:

  • Sheep (most severely affected)

  • Cattle

  • Goats

  • Deer

Sheep usually show more severe clinical signs, and mortality can be high in severe outbreaks.

Cattle often act as reservoir hosts, sometimes showing mild or no symptoms but spreading the virus through midges.

5. Clinical Signs

In Sheep

Common signs include:

  • Fever

  • Swelling of face, lips and tongue

  • Blue or purple tongue

  • Lameness

  • Nasal discharge

  • Mouth ulcers

  • Drooling

  • Weakness

  • Abortion

  • Death in severe cases

In Cattle

Signs may include:

  • Fever

  • Reduced milk yield

  • Mouth ulcers

  • Nasal discharge

  • Lameness

  • Abortion or birth defects

Some cattle may show few or no visible signs.

6. Impact on Farms and Trade

Bluetongue can have major economic impacts, including:

  • Reduced productivity

  • Animal illness and deaths

  • Movement restrictions

  • Export trade impacts

For example, disease detection can affect livestock movements or international trade conditions.

7. Control and Prevention

Vaccination

  • Vaccination against BTV-3 is permitted in Ireland from 2026.

  • Farmers should discuss vaccination strategies with their Private Veterinary Practitioner (PVP).

Vector Control

Measures to reduce midge exposure:

  • House animals during peak midge activity (dusk and dawn)

  • Use insecticides where appropriate

  • Improve drainage around farms

  • Avoid wet areas where midges breed

Biosecurity

  • Monitor animals regularly

  • Isolate animals with suspicious symptoms

  • Avoid unnecessary animal movements

  • Maintain good herd health monitoring

8. What Farmers Should Do

If bluetongue is suspected:

  1. Contact your vet immediately

  2. Report suspected cases to the Department of Agriculture, Food and the Marine (DAFM)

  3. Do not move affected animals until veterinary advice is given.

Bluetongue is a notifiable disease, meaning suspected cases must be reported to authorities.

9. Key Points to Remember

  • Bluetongue is a vector-borne viral disease of ruminants.

  • It is spread by biting midges, not direct animal contact.

  • Sheep show more severe symptoms than cattle.

  • No risk to human health or food safety.

  • Vaccination is available in Ireland from 2026.

  • Early detection and reporting are essential.

For further information please visit: https://www.gov.ie/en/department-of-agriculture-food-and-the-marine/publications/bluetongue-virus/