As stated by the State Veterinary Administration (2025), the examination of samples from dead hares (Lepus europaeus) from the Znojmo region in the Czech Republick has now confirmed the presence of the myxomatosis virus in the animals. For hares, this currently represents an exceptionally serious disease, which in the past was capable of almost exterminating the population of the wild rabbit (Oryctolagus cuniculus). The spread of the disease among free-living hares cannot be prevented due to transmission by insects (e.g., mosquitoes). Domestic rabbits can be preventively vaccinated, which is recommended to breeders by the State Veterinary Administration.
Infections with the virus in free-living European brown hares have been reported only sporadically and usually correlated with a high prevalence of the virus in sympatric wild rabbit populations (Wibbelt & Frölich, 2005). This was also the case described in 2014 in Great Britain (Barlow et al., 2014). Earlier documented cases of myxomatosis in hares were reported by Lucas et al. (1953) in Spain by Jacotot et al. (1954) in France. Rossini et al. (2024) describe a case from 2018, when the Corsican hare (Lepus corsicanus) was infected.
The first modern outbreaks of myxomatosis associated with mass mortalities in hares were recorded in Iberian hare (Lepus granatensis) populations between mid-July and the end of September 2018. Specifically, in 12 geographically close hunting areas located in the province of Córdoba. In total, around 530 dead hares were found during this period, with analysis confirming myxomatosis virus infection in all tested individuals. The overall mortality was estimated at 56.7%, while the case fatality rate of infected individuals reached 69.7% (García-Bocanegra et al., 2019). Just three months later, in October 2018, the virus was detected in Iberian hares in Portugal (Carvalho et al., 2019).
In 2023, four European brown hares were found and tested in North Rhine-Westphalia, showing signs of infection with the myxoma virus (Fischer et al., 2025). However, these cases were considered isolated findings, similar to the one in the United Kingdom (Barlow et al., 2014). As reported in the study Recombinant Myxoma Virus in European Brown Hares, 2023–2024. Emerging Infectious Diseases (Fischer et al., 2025), from August 2024 onwards, cases of diseased and dead hares showing symptoms of myxomatosis were reported along the German–Dutch border. The disease was subsequently confirmed in each of the 104 tested individuals from Germany and the Netherlands. The disease is now spreading radially from the German–Dutch border region. The introduction of the virus into this area may date back as far as September 2020 and is assumed to have been caused by human activity. This outbreak is also the first known to us in which mass infection and mortality occurred in the European brown hare, rather than in the Iberian hare.
In the spring of 2025, due to the high number of deaths, the occurrence of myxomatosis in European brown hares was recorded northeast of Vienna (Auer et al., 2025).
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