The present invention provides an isolated canine influenza virus of subtype H3N8 comprising an HA having SEQ ID NO: 4 or an amino acid sequence that is greater than 99% identical to SEQ ID NO: 4, with the proviso that the amino acids at positions 94 and 233 are identical to SEQ ID NO: 4； a composition comprising attenuated or inactivated virus； isolated or purified HA, NM, NP, Ml, NSl, PA, PBl, and PB2 proteins and fragments thereof and compositions comprising same or nucleic acids, optionally as part of a vector, encoding same； and a method of inducing an immune response to canine influenza virus in an animal comprising administering to the animal an aforementioned composition.
