African horse sickness virus is a double-stranded RNA virus which causes a non-contagious, infectious arthropod-borne disease of equines and occasionally dogs. Nine distinct, internationally recognised serotypes of the virus have so far been identified. This book is based upon the findings of two programmes funded by the European Commission. It will be of value not only to the specialist research workers but also to veterinary workers dealing with control and to legislators seeking to promote safe international movement of equines. The topics covered include state-of-the-art discussions on diagnostics, vaccines, molecular biology, vector studies, and epidemiology.