Remarks about West Nile Disease passive surveillance in horses. The experience of Emilia-Romagna 2008-2010

West Nile Disease (WND) has been considered in Italy a re-emerging zoonosis, due to West Nile Virus (WNV) appearance on national territory in summer of 2008, 10 years after the last epidemic outbreak in Tuscany. WNV cycle involves birds and mosquitoes, however several mammals, as humans and horses, can be infected showing influenza-like symptoms and sometimes severe meningoencephalitis. Main objective of veterinary surveillance is the early detection of WNV circulation, in order to manage specific preventive measures. One of the most effective tools for this purpose is the passive surveillance on horses (OM 5/11/2008). Data about WND confirmed cases in horses in Emilia-Romagna region between 2008 and 2010 were examined. Clinical features resulted variable and unspecific. More information and awareness of veterinary practitioners working in the equine field will make this surveillance system more effective for early detection of new cases in the region. The aim of this article is to make available to practitioners some diagnostic tools, useful to identify neurological syndrome and to report suspected cases of WND in horse.