Just like people, dogs can be affected by different strains of influenza, a highly contagious respiratory infection. There are two strains of canine influenza known to affect dogs internationally. H3N8 broke out around 2004 in Florida and continues to cause sporadic disease; H3N2, a milder strain first seen in Chicago in 2015, is closely related to an Asian strain first identified in 2006. These viruses are different strains of Influenza Type A. Whether or not H3N2 will have the staying power of H3N8 remains to be seen.