Equine influenza viruses are a group of highly contagious infectious agents that infect horses, causing a respiratory disease known as equine influenza. These viruses belong to the Orthomyxoviridae family, specifically the genus Influenzavirus A. Equine influenza viruses are RNA viruses that have a segmented genome.
Equine influenza is a major respiratory disease affecting horses around the world. It is characterized by high fever, coughing, nasal discharge, and lethargy. The disease spreads rapidly among horses housed in close proximity, such as in racing stables, equestrian events, or training facilities. Equine influenza viruses primarily spread through respiratory droplets, which can be released through coughing or sneezing, and can remain viable in the environment for 48 hours.
The two main subtypes of equine influenza viruses are H7N7 and H3N8. H7N7 caused the first recorded outbreak of the disease in horses in the late 19th century, while H3N8 emerged in the late 1950s and is the more common subtype seen today. Vaccination is available to protect horses against equine influenza, but due to the constant evolution of the virus, regular updates of the vaccine are necessary.
Equine influenza can have severe economic implications, causing loss of performance, productivity, and revenue for horse owners and industries that depend on horse-related activities. Additionally, there are concerns about the potential transmission of equine influenza viruses to other species, including humans, although human infection is rare.
