Bornaviruses cause a lethal form of encephalitis, called Borna disease, among horses and sheep. To date there have been only a few reported cases in Austria. Recently, however, four horses were afflicted in the same area of Upper Austria within just two years. Tests conducted on local shrews, the only known reservoir host for the virus, confirmed the suspicion of a local viral reservoir. A large proportion of the small mammals investigated by the researchers from Vetmeduni Vienna tested positive for Bornaviruses, which were revealed to be genetically distinct from strains found in neighbouring regions such as Bavaria. The study, conducted in cooperation with the Austrian Agency for Health and Food Safety (AGES) and local veterinarians, and published in the journal Emerging Microbes & Infections, documents this rare outbreak of Borna disease in a new endemic area in Austria.