Equine owners in that area are also advised to use a fly-wipe on their animals to help prevent the spread of the disease. EIA is a viral disease of horses, mules and donkeys. It has been recognized in the United States for 80 years and other countries prior to that. The virus is spread under natural conditions by insect vectors.
Transmission is mechanical and requires a carrier animal, a vector, and a susceptible host.
It is not spread by animal waste or harbored by physical facilities. The disease may be acute, subacute, or chronic. The incubation period is generally 12-15 days but may extend up to 2 months. The acute form begins with a temperature elevation, followed by weakness, uncoordination, rapid respiration, weight loss, anemia, and subcutaneous edema. Death may result in 15-30 days or the animal may develop a subacute form of the disease characterized by marked anemia.