Influenza A Virus in Horses

Yes, horses can get the flu too. Horses that are inflected can run a fever, have a dry, hacking cough, have a runny nose, become somewhat depressed and reluctant to eat or drink for several days. Equine influenza is rarely fatal and horses usually recover within in two to three weeks.

Equine influenza (horse flu) is the disease caused by two strains of influenza A that circulate globally in horses. Because equine influenza is historically not known to affect humans, it has deservedly has its own system of naming the subtypes: Influenza A/Equine-1 (caused by H7N7)  and Influenza A/Equine-2 (caused by H3N8). Influenza A/Equine-1 has not been isolated since 1980. Influenza A/Equine-2 was first recognized in 1963 as a cause of widespread epidemics and has subsequently become endemic in many countries.

While outbreaks of equine influenza would have far greater impact in the past when transportation of people and goods nearly always relied on horses, these outbreaks may still have a considerable economic impact. Horse races (and gambling) would be severely affected.

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. Prevention via vaccination and adherence to strict hygienic procedures may curb the spread of equine influenza.

The problem with the Influenza virus is that it constantly evolves and its potential to cross species barriers is well known. The first hurdle has been taken when the Equine influenza virus adapted enough in 2004 to infect dogs. Then it has crossed the species barrier to infect other mammals such as pigs and camels and therefore may also pose a threat to humans.