Borna disease (BD) is a rare immunopathological disorder of the central nervous system (CNS) caused by infection with Borna disease virus (BDV) and histologically characterized by mononuclear encephalomyelitis. BD primarily affects equines and sheep in well defined endemic areas of central Europe, but BDV infections have also been reported in other host species including humans, as well as in non endemic regions. In this paper recent data on the pathogenesis of BD are reviewed and the current situation in Switzerland and the Principality of Liechtenstein is summarized.