In the UK, Equine Viral Arteritis (EVA) is notifiable by law. It is a contagious disease caused by the equine arteritis virus (EAV). The virus occurs worldwide. There are no human health implications associated with this disease and only Equidae are affected. In the UK the latest outbreaks were confirmed in a stallion in Staffordshire on 2 August 2010 and a stallion in West Sussex on 8 December 2010.
The variety and severity of clinical signs of EVA vary widely. Infection may be obvious or there may be no signs at all. Even when there are no signs, infection can still be transmitted and stallions might still become shedders.