First Swedish case of fatal equine parasitic encephalitis by Halicephalobus gingivalis.

Background: Halicephalobus gingivalis is a nematode with zoonotic potential which can cause fatal opportunistic infections in various mammals. The parasite has never been diagnosed in Sweden, in any species, prior to the presented case.

Case Presentation: An imported 21-year-old Icelandic mare developed severe neurological signs.