National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2012

01. Detection of equine infectious anaemia virus in native Japanese ponies


In 2011, horses infected with equine infectious anaemia virus (EIAV) were detected for the first time in 18 years in Japan. The two infected horses were kept at different farms, but both had originated from a herd of wild native Japanese ponies (Misaki breed). Therefore, we investigated the prevalence of EIAV infection among Misaki ponies. Twelve of the 96 Misaki ponies were found to be infected with the virus. Although wild animals are not bound by the Domestic Animal Infectious Disease Control Law in Japan, the infected ponies were culled to eradicate EIA from Japan. Molecular phylogenetic tree analysis of partial sequences of the group-specific antigen (gag) region showed that the virus that the Misaki ponies were infected with, was similar to isolates prevalent before the 1960s in Japan and did not originate from outside of Japan.
(Viral Disease and Epidemiology Research Division)


  • Murakami K. et al. (2012) Veterinary Record 171 (3):72 (site as doi:10.1136/vr.100459)
  • Murakami K. et al. (2011) Animal Hygiene Weekly 3183:396-398