Equine Infectious Anemia (EIA), or swamp fever, is a viral disease that occurs worldwide. It is a bloodborne infection, which means that the virus can be found free in the plasma. Infection with EIA virus appears to persist for life and, in nature, blood-feeding insects initiate most infections by mechanical transfer of infective blood between horses in close proximity. Horseflies and deer flies appear to be the most efficient vectors in transmitting the disease. EIA virus has not been shown to multiply in insects; infected equids (horses, zebras, donkeys, etc.) appear to be the only reservoir of the virus. EIA can also be transmitted by iatrogenic infection, such as contaminated needles and surgical instruments.

Clinical Signs

• Repetitive fever bouts
• Platelet count reductions
• Petechial hemorrhages
• Depression
• Weight loss and cachexia
• Labored breathing
• Pounding heartbeat and exhaustion
• Anemia

Treatment

No specific treatment or vaccine is available.

Prevention

Prevention consists of monitoring the horse's health and testing for disease annually or biannually with EIA (Coggins) Test. Use of fly repellent on horses is also recommended.

See Equine Infectious Anemia (Coggins Disease) for more information.