Equine arteritis virus

Equine viral arteritis (EVA) is a disease of horses caused by an RNA virus of the genus Arterivirus. The virus which causes EVA was first isolated from horses in Ohio in 1953 but the disease has afflicted equine animals worldwide for centuries. It has been more common in some breeds of horses in the United States, but there is no breed "immunity". In the UK, it is a notifiable disease. There is no known human hazard.

The virus which causes EVA is the Equine Arteritis Virus (EAV). Arteriviruses are small, enveloped, animal viruses with an icosahedral core containing a positive-sense RNA genome. The family includes Equine arteritis virus (EAV), porcine reproductive and respiratory syndrome virus (PRRSV), lactate dehydrogenase elevating virus (LDV) of mice and simian haemorrhagic fever virus (SHFV).

Infected horses show variable symptoms including:

Some horses show no symptoms.

There are a number of routes of transmission of the virus. The most frequent is the respiratory route. The virus can also be spread by the venereal route, including by artificial insemination. Stallions may become carriers.

Because of the variability of symptoms, diagnosis is by laboratory testing. Blood samples, nasal swabs and semen can be used for isolation of the virus, detection of the viral RNA by polymerase chain reaction (PCR), and detection of antibodies by ELISA and virus neutralisation tests.

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