There have been two canine influenza viruses (CIVs) which have caused epidemics of disease in dogs. The first was an H3N8 CIV which was derived from an equine influenza virus (EIV) that infected dogs in Florida around 1999, and that virus went on to cause an epidemic which died out around 2016.
The second CIV was caused by an avian influenza virus that transferred to dogs around 2005 in China or Korea. That virus caused an epidemic of disease in dogs in China and Korea, and subsequently was transferred to dogs in the USA and Canada. Since 2015 the H3N2 CIV appears to have been repeatedly introduced to the USA from Korea and from China. Currently (2023) it appears that the virus is still circulating in China and the USA. has died out in Korea (around 2017).