• Fact SheetEven when clinically ill horses recover from
West Nile encephalitis, up to 40 percent of
them may have residual effects, such as gait
abnormalities and a change in their usual
temperament or behavior.
• Surveillance and ReportingThe Michigan Department of Agriculture monitors for West Nile virus and other arboviruses (insect-borne viruses) in horses.
• WNV in HorsesHorses have proven uniquely susceptible to West Nile virus infection, comprising more than 99 percent of veterinary mammalian cases.
• Laboratory TestingLive and dead horses suspected of having West Nile virus infection are tested at Michigan State University, Diagnostic Center for Population and Animal Health.
• WNV Equine Testing ResultsResults of West Nile virus testing for 2003-2008 on horses submitted to Michigan State University, Diagnostic Center for Population and Animal Health. Table is updated as data becomes available.
• West Nile Virus Equine Surveillance MapsMaps of 2002-2010 West Nile virus testing results in horses submitted to Michigan State University, Diagnostic Center for Population and Animal Health.