Whether signs are shown or not, equine influenza infection can result in days or weeks off work and the virus rapidly spreads to other horses by nasal aerosol (coughing). (cedarbayouanimalclinic.com)
Dog influenza virus is actually mutated form an existing H3N8 strain of Equine Influenza Virus; which was discovered 40 years ago. (dog-health-handbook.com)
They are two types of equine influenza virus (EIV): H7N7 (subtype 1) and H3N8 (subtype 2). (ivcjournal.com)