Research and analysis

Risk assessment of the annual likelihood of equine infectious anaemia virus introduction into Great Britain from EU and EFTA member states in December 2025 (executive summary)

Published 21 April 2026

Applies to England, Scotland and Wales

This summary outlines a qualitative risk assessment which evaluated the likelihood of equine infectious anaemia virus (EIAV) being introduced into Great Britain (England, Scotland and Wales) from European Union (EU) and European Free Trade Association (EFTA) member states. It also considered the subsequent likelihood of exposure for live equids (horses and donkeys) within Great Britain and the potential consequences of an outbreak. The assessment reflects the situation as of December 2025.

It was necessary to make several assumptions in the risk assessment, such as compliance with trade restrictions and other legal requirements (except when assessing illegal trade routes). A detailed breakdown is available in the full risk assessment, which can be requested by emailing ukassurance@defra.gov.uk.  

Background

Equine infectious anaemia (EIA) is a bloodborne, retroviral disease affecting members of the Equidae family. The clinical presentation is highly variable.

EIA is a WOAH-listed disease, which is notifiable in Great Britain and the EU. In the EU, EIA country prevalence estimates range from 0% to 6.31%. In Great Britain, EIA was last reported in 2012, initially in a single horse in Cornwall presenting with clinical signs. A second case was subsequently confirmed in a horse in Devon.

The following pathways were considered as part of the entry and exposure assessments:

• legal trade in live equids
• illegal trade in live equids
• legal trade in equid germplasm, such as semen and embryos
• Iatrogenic routes (blood and blood products and contaminated veterinary medical equipment)
• insect vectors, such as horse flies

Hazard

Equine infectious anaemia virus I

Risk questions

1. What is the annual likelihood of EIAV introduction at least once into Great Britain from EU and EFTA member states?

2. What is the annual likelihood of EIAV exposure for live equids in Great Britain?

3. What are the potential consequences of an EIA outbreak in Great Britain?

Main findings

Entry pathways

The most likely pathway for EIAV introduction was considered the illegal trade in live equids, with a low annual likelihood (event is rare but does occur) and high uncertainty. This reflects the number of live equid imports with absent or invalid health certification, some of which may only be detected after arrival.

The annual likelihood of entry associated with legal trade in live equids and in equid blood and blood products was considered very low (event is rare but cannot be excluded), with medium uncertainty.

All remaining pathways were assessed as negligible (so rare that they do not merit consideration), with low to medium uncertainty.

Exposure pathways

The overall annual likelihood of an equid being exposed to EIAV in Great Britain was considered medium (event occurs regularly), with high uncertainty. This was due to the illegal live equid pathway. There were several reasons why this was considered a likely exposure route, including the possibility that owners of illegally imported equids may choose not to report signs of EIA or may ignore post-import quarantine and testing requirements.

The uncertainty was high due to the lack of data concerning illegal live equid movements in Great Britain and the conditions in which the animals are kept, including their quality of veterinary care.

Consequence assessment

An EIA outbreak is not expected to lead to a national export ban on live equids or equid products, as the disease freedom requirements for trade in the WOAH Terrestrial Code only apply at the premises level.

National food security impacts are also unlikely, as horses are not generally raised for meat or dairy in Great Britain.

The rate of EIA spread can be relatively slow. For example, during the last outbreak in Great Britain in 2012, there was no evidence of onward spread, despite the infected animals likely having been imported in 2008. However, outbreak management costs can be substantial.

The 2006 outbreak in Ireland cost an estimated €1.065 million. This included managing 38 cases across 18 premises in nine counties, along with extensive testing and operational response activities. More than 57,000 samples were tested to support disease control and the return to disease-free status.

Given the potential social, economic and animal welfare impacts, the consequences of an EIA outbreak in Great Britain are assessed as moderate, with medium uncertainty.

Key uncertainties

Entry assessment

The main uncertainties in this section were:

• EIA prevalence within EU and EFTA member states, given the limited prevalence studies, especially for top trading partners, such as Germany   
• the proportion of live equids in EU and EFTA member states that undergo routine pre‑export EIAV testing
• the number of non‑compliant live equid consignments intercepted before arrival in Great Britain, including any that are smuggled into the country without IPAFFS pre‑notification
• the likelihood of EIAV transmission through germplasm, especially ova and embryos, given the limited amount of research  
• the exact proportion of untreated equid blood and blood product imports from EU and EFTA member states

Exposure assessment

The main uncertainties in this section were:

• the frequency with which transfer of infected equid blood might contribute towards exposure to EIAV from a legally or illegally imported live equid  
• illegal live equid movements in Great Britain and the conditions under which the animals are kept, including their level and quality of veterinary care        
• the level of post-import treatment applied to equid blood and blood products to inactivate pathogens like EIAV
• the likelihood of EIAV transmission through germplasm, especially ova and embryos, given the limited amount of research   

Consequence assessment 

The main uncertainties in this section were the:

• likely size of an EIA outbreak and rate of spread within Great Britain
• economic impacts of an EIA outbreak, given the lack of data from previous outbreaks in Great Britain