The highly contagious equine influenza virus H3N8 was found to have been the cause of Greyhound race dog fatalities from a respiratory illness at a Florida racetrack in January 2004.

高传染性的马流感病毒H3N8引起的犬流感最早被发现于2004年一月的举行于佛罗里达的灵缇犬比赛中。被感染的犬只发生呼吸疾病症状。