Equine Influenza - Causes

Causes

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.