Outbreak of Equine Infectious Anemia

August 19, 2025 – Tübingen District, Baden-Württemberg 

A case of Equine Infectious Anemia (EIA) – also known as infectious anemia of equids – has been confirmed in a mare in the district of Tübingen (Baden-Württemberg). This is the first confirmed case in Germany since 2017. The national reference laboratory, the Friedrich-Loeffler-Institute (FLI), has verified the diagnosis.

The affected mare had been imported from Bulgaria about two years ago and has been euthanized. All horses tested so far that had direct or indirect contact with the infected mare in the Tübingen district or surrounding regions have tested negative for EIA. In the Rems-Murr district and the district of Ludwigsburg, where contact horses were also identified and are under surveillance, the initial blood tests likewise produced negative results.

The authorities are carrying out a second round of blood tests in these herds, about four weeks after the last possible exposure. Two other horses that had earlier contact with the infected mare and whose premises were placed under precautionary restrictions have also been tested. In one case, the restriction was lifted after a negative result. For the second horse in the Ludwigsburg district, the final result is still pending.

What is Equine Infectious Anemia?

EIA is a viral disease affecting horses and other equids such as donkeys and zebras. The virus is distributed worldwide but occurs more frequently in certain regions. In Romania, the disease is considered endemic, with new cases reported on a regular basis. Outbreaks are also occasionally recorded in Italy and France. In Switzerland, the disease has only been documented once since the introduction of mandatory reporting in 1994 – in June 2017, the first case since 1991.

The disease can occur in two forms. In the acute, severe form, horses usually develop high, fluctuating fever, muscle weakness, coordination problems, trembling, and yellowish to reddish discoloration of the oral mucosa. In some cases, sudden death may occur.
The chronic form progresses more slowly and often less noticeably. Typical signs include weight loss, fatigue, and a marked drop in performance. A characteristic feature is that fever often returns after physical exertion. Even when outwardly healthy, infected horses continue to carry the virus.

How is the disease transmitted?

Transmission usually occurs via insect bites, such as those of mosquitoes, flies, or horseflies. Prolonged close contact between horses can also spread the infection. All secretions of infected animals are contagious, as is the semen of infected stallions. Once infected, horses generally remain carriers and can shed the virus for life. Transmission to unborn foals in utero or through milk is possible but rare.

There is currently no vaccine and no cure for EIA. To prevent recurrence, strict control measures apply in Switzerland and across the EU, including mandatory culling of infected animals. For this reason, special caution is advised when importing horses, particularly from regions where the disease occurs regularly.

Relevance for Switzerland

The current outbreak in Tübingen is not far from the Swiss border. Although Germany is not considered an endemic area for EIA, individual cases do occur occaisionally following imports.

For horse owners in Switzerland, this means keeping a particularly close eye on imports from high-risk regions – especially Eastern Europe. Tournaments, transport, or clinic stays near outbreak areas may also pose a risk. It is therefore advisable to actively check the current disease situation before any planned stay. Only through consistent monitoring and close cooperation between horse owners, veterinarians, and authorities can the introduction of this incurable disease into Switzerland be prevented.

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