Equine influenza is caused for Equine Influenza Virus type-A. There are two subtypes of equine influenza virus; A/Equi 1/H7N7, and A/Equi 2/H3N8. Both subtypes have caused disease. Equine influenza appears similar to a range of other viral respiratory diseases. Most of these viruses produce rather mild signs which include a discharge from the nose and coughing. In countries where breeding and racing horses is a major industry, outbreaks of the disease can result in significant economic loss.