quine Viral Arteritis: Diagnostic and Control Measures

Abstract

A relatively large scale epizootic of equine viral arteritis (EVA) which occurred in Thoroughbreds at Arlington Park Race Course in the USA in 1993 [50], just after the first outbreak of EVA in non-Thoroughbreds in the United Kingdom [40, 95] remains vivid in our memory. It had been considered that the United Kingdom, Ireland, Australia, New Zealand and Japan were the few countries left free from EVA over the past few dozen years. However, serological evidence of EVA was found in Standerdbreds in Australia and New Zealand in 1990 and EVA has been in Australia since 1975, while confirmed clinical EVA was not recognized [42, 68]. The majority of horses infected with equine arteritis virus (EAV) seem to have a mild or subclinical form all over the world [5, 6, 12, 33, 39, 42, 45, 49-51, 53, 60, 64, 70, 73, 98]. In contrast, fatal cases in foals and a neonatal foal have been reported in Poland [34, 35] and the USA [93]. Furthermore, because EVA adversely affects racing [47, 50, 64] and results in a high rate of abortion in pregnant mares [9, 20, 34, 46], an outbreak of EVA in such horse populations may lead to significant economic loss. In recent years, there have been considerable number of international movements of horses for the purpose of trading, breeding and competition. Such movements could provide extensive spread of contagious diseases in horse populations which may be highly susceptible to exotic infectious diseases. Although only a few countries in the world including Japan have remained free from EVA, this article describes the clinical features and diagnosis of EVA, as well as the prevention and control of EVA, thus providing information which will be useful in minimizing suffering from a serious outbreak of EVA should it occur in horse populations that have been free of EVA.