AHS is a non-contagious arthropod-borne disease of equidae. The causal agent is an [[African Horse Sickness|orbivirus]] existing in nine serotypes. The occurrence of AHS is both cyclical and seasonal and dependent on the vector, usually [[Biting Flies#Ceratopogonidae|''Culicoides'']]. Equine encephalosis, caused by a related orbivirus, follows a similar distribution and epidemiology to African Horse Sickness and can present with similar signs. | AHS is a non-contagious arthropod-borne disease of equidae. The causal agent is an [[African Horse Sickness|orbivirus]] existing in nine serotypes. The occurrence of AHS is both cyclical and seasonal and dependent on the vector, usually [[Biting Flies#Ceratopogonidae|''Culicoides'']]. Equine encephalosis, caused by a related orbivirus, follows a similar distribution and epidemiology to African Horse Sickness and can present with similar signs. |