The Equine Infectious Disease Surveillance (EIDS) network has confirmed that equine influenza (EI) continues to spread across the UK, with 74 laboratory-confirmed outbreaks identified since the beginning of April 2026.
The latest update, published on 28 May, reveals that while weekly outbreak numbers may be showing signs of slowing, the disease remains active and continues to spread into new areas of the country.
Importantly, EIDS is also aware of a further 26 confirmed outbreaks that are not included in the official figures because outbreak details and/or permission for anonymous reporting have not yet been received. This means at least 100 confirmed outbreaks are currently known to the surveillance network.
New Areas Continue to be Affected
The latest report covers outbreaks recorded between 29 March and 27 May 2026 and includes cases from multiple counties across the UK.
Since the previous update on 21 May, EIDS has received approval to report five additional confirmed outbreaks across five counties. Two of those counties had not previously reported equine influenza during the current outbreak period, highlighting the continued geographical expansion of the disease.
While the number of newly confirmed outbreaks appears to be slowing, EIDS cautions that the situation remains fluid.
A similar pattern was observed during the major UK equine influenza outbreak in 2019, where an apparent decline in cases was followed by a subsequent resurgence.
The surveillance team also notes that reporting delays and reporting fatigue can contribute to an apparent reduction in confirmed cases.
Horse Movement Remains a Key Risk Factor
Recent horse movement continues to emerge as one of the most significant factors associated with disease spread.
Of the 74 confirmed outbreaks:
- 44 (59%) involved horses with a recent history of travel
- 27 had no travel history available
- Just 3 involved horses with no recent travel history
These findings continue to support horse movement as a major driver of disease transmission between premises and regions.
However, the occurrence of outbreaks in horses with no recent travel history demonstrates that equine influenza should remain a consideration even within apparently closed populations.
Vaccination Data Highlights Ongoing Concerns
The latest outbreak data also provides insight into vaccination status:
- 46 outbreaks (62%) involved unvaccinated horses
- 8 outbreaks (11%) involved vaccinated horses
- 2 outbreaks involved a mixture of vaccinated and unvaccinated horses
- 18 outbreaks had an unknown vaccination status
According to EIDS, the predominance of outbreaks involving unvaccinated horses reinforces the importance of maintaining up-to-date vaccination programmes across all sectors of the equine industry.
Rapid Testing Supporting Surveillance
Eleven of the confirmed outbreaks were diagnosed using rapid in-house point-of-care tests, including LAMP and iiPCR technology, allowing quicker identification of cases and supporting more rapid disease management decisions.
EIDS continues to encourage veterinary practitioners to test and report suspected cases to ensure an accurate picture of disease activity across the UK.
What Horse Owners Should Know
Equine influenza is one of the most contagious respiratory diseases affecting horses and can spread rapidly where horses mix, travel or compete.
Clinical signs may include:
- Fever
- Coughing
- Nasal discharge
- Lethargy
- Reduced performance
- Loss of appetite
Horse owners are advised to:
- Check that vaccinations are current and compliant with competition requirements
- Monitor horses closely for signs of respiratory illness
- Isolate any horse showing symptoms
- Seek veterinary advice promptly
- Maintain good biosecurity practices, particularly when travelling or attending events
With new counties continuing to report cases and further outbreaks awaiting publication, EIDS is urging horse owners, yard managers and veterinary professionals to remain vigilant and continue supporting surveillance efforts.
Veterinary surgeons can access free outbreak management advice through EIDS, while free laboratory testing for suspected cases remains available through the HBLB Equine Influenza Surveillance Scheme, run by EIDS in conjunction with Rossdales Laboratories.
