However, serum collected from racing Greyhounds between 1984 and 2004 and tested for canine influenza virus (CIV) in 2007 had positive tests going as far back as 1999.

然而，在1984年至2004年间从灵缇赛犬的血浆测试中发现犬流感病毒（CIV）的感染可以被追溯到1999年。

youdao

Canine influenza is caused by varieties of Influenzavirus a, such as equine influenza virus H3N8, which in 2004 was discovered to cause disease in dogs.

犬流感由各种甲型流感病毒引起，如马流感病毒H3N8。该病毒于2004年被发现能引起犬流感。

youdao