Equine viral arteritis

Equine viral arteritis is a notifiable disease

Under Queensland legislation, if you suspect the presence of this disease in horses, you must report it to Biosecurity Queensland.

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Equine viral arteritis (EVA) is an acute, contagious, viral disease of horses.

EVA is a notifiable disease under legislation and all suspect and confirmed cases in horses should be reported to Biosecurity Queensland.

Where the disease occurs

The virus is present in horse populations in many countries throughout the world. Although EVA virus occurs in Australia, disease associated with EVA virus infection has never been recorded here, which suggests that the strains of virus circulating in Australia are of low virulence.

The disease in animals

Exposure to EVA virus may or may not result in clinical disease. When clinical signs occur they are characterised by fever, depression, respiratory symptoms, swelling of the legs especially the hind legs, conjunctivitis and nasal discharge. The virus causes damage to the smaller blood vessels resulting in oedema and haemorrhage in many tissues and organs. Some strains of the virus cause abortion and death in young foals.

How the disease spreads

Transmission of EAV infection can occur by respiratory, venereal, congenital, or indirect means. Outbreaks of EVA are usually linked to the movement of animals or the shipment of semen. Viral transmission can be widespread at racetracks or on breeding farms.

Carrier stallions are viral reservoirs and are primarily responsible for persistence of the virus in different horse populations throughout the world.


Blood samples and nasopharyngeal and conjunctival swabs should be collected for virus isolation and the detection of antibodies.

Control of the disease in animals

There is no specific treatment for EVA and most affected horses recover completely. Treatment for stallions may be advisable to avoid short-term reduced fertility.

Most prevention and control programs are focused on preventing or curtailing dissemination of equine arteritis virus in breeding populations, to minimise the risk of virus-related abortion or death in young foals and establishment of the carrier state in stallions.

Horse semen should be tested and shown to be free of the disease.

Can people get the disease?


Last updated 20 January 2016