TRANSMISSION
The primary route of transmission of equine infectious anemia virus is by blood-feeding insects such as horseflies, deer flies, stable flies and mosquitoes. These insects carry the virus in blood on their mouthparts and can transfer it from an infected horse to a naïve one (Merck Veterinary Manual 2012). Flies, especially those that cause extreme irritation, are the most risky for transfer. When these flies are feeding, because of the pain or annoyance, they are brushed away causing them to look for another blood source to finish feeding from, thus effectively transferring the virus (Merck Veterinary Manual 2012)
Another method of transmission is iatrogenic. The reuse of needles and surgical equipment including teeth floating instruments can transfer virus if not disinfected between horses. Blood transfusion can also be a source (AAEP undated).
Foals can become infected from their dams in two ways: in utero, or via the mare’s milk. The virus and/or antibodies to the virus can be passed to the foal via suckling.
EIAV is also found in semen, which leads us to believe venereal transmission is likely possible (Iowa State University 2009).
Another method of transmission is iatrogenic. The reuse of needles and surgical equipment including teeth floating instruments can transfer virus if not disinfected between horses. Blood transfusion can also be a source (AAEP undated).
Foals can become infected from their dams in two ways: in utero, or via the mare’s milk. The virus and/or antibodies to the virus can be passed to the foal via suckling.
EIAV is also found in semen, which leads us to believe venereal transmission is likely possible (Iowa State University 2009).