Failure in the Development of Carrier State of Equine Viral Arteritis in Colts

Abstract

An attempt was made as a preliminary examination to establish the carrier state o f equine viral arteritis (EVA) in 5 colts infected intranasally with the 84KY-Al strain of the equine arteritis virus (EAV). Persistent infection was monitored by virus isolation and its longest duration was positive in the plasma of a colt one to three weeks after infection. EAV was distributed through all body tissues and high titered virus was detected in the lymphoid tissue rather than the reproductive tissue one week after infection. However, no virus was recovered from any site in the body tissues, including the reproductive tract of 4 colts 4 months after infection. This suggested that persistent infection would not occur in young colts. The carrier state of EVA was discussed with regard to essential conditions, e.g. whether the presence of testosterone, testes or both are involved.