About of Equine influenza | Definition of Equine influenza

Source:  About of Equine influenza | Definition of Equine influenza    Tag:  epizootic disease
Equine influenza ( Horse flu) is the disease caused by strains of Influenza A that are enzootic in horse species. Equine influenza occurs globally, and is caused by two main strains of virus: equine-1 (H7N7) and equine-2 (H3N8). The disease has a nearly 100% infection rate in an unvaccinated horse population with no prior exposure to the virus.

While equine influenza is historically not known to affect humans, the impact of an outbreak would have been devastating. Since people heavily relied upon horses for communication (postal service), military (cavalry) and general transport, the social and economic impact of widespread equine disease would have been devastating. However, in modern times the ramifications of equine influenza are most clear in the modern racing industry.

Equine influenza is characterized by a very high rate of transmission among horses, and has a relatively short incubation time of 1–5 days.

Horses with horse flu can run a fever, have a dry hacking cough, have a runny nose, and become depressed and reluctant to eat or drink for several days, but they usually recover in 2 to 3 weeks.

An 1872 report on equine influenza describes the disease as:
("An epizootic specific fever of a very debilitating type, with inflammation of the respiratory mucous membrane, and less frequently of other organs, having an average duration of ten to fifteen days, and not conferring immunity from a second attack in subsequent epizootics."James Law, Report of the Commissioner of Agriculture for the year 1872)

Equine influenza is caused by several strains of the Influenza A virus endemic to horses. Viruses that cause equine influenza were first isolated in 1956. The viruses can cross the species-barrier to cause an epizootic disease in humans, and recently, in dogs.

The equine-1 virus affects heart muscle, while the equine-2 virus is much more severe and systemic.

The disease is primarily spread between infected horses. Exposure to infected waste materials (urine and manure) in stables leads to rapid spread of the disease.