In April 2004, a group of researchers at the University of Florida reported that preliminary findings
suggested equine influenza virus had jumped the species barrier to dogs and caused a respiratory tract disease outbreak, killing eight Greyhounds in January 2004 at a track in Jacksonville, Fla..
Genetic analysis shows that the original canine
influenza virus is closely related to
equine influenza virus,
suggesting that it evolved from
equine influenza virus and jumped species.