Equine influenza


Equine influenza is prohibited matter.

Under Queensland legislation, if you suspect the presence of this disease in any species of animal, you must report it to Biosecurity Queensland on 13 25 23 or contact the Emergency Animal Disease Hotline on 1800 675 888.

Equine influenza (EI) is a highly contagious though rarely fatal respiratory disease of horses, donkeys, mules and other equidae. The detection of EI in Australia is regarded as an emergency and every attempt will be made to eradicate the disease. National arrangements are in place to support such a response.


An influenza A virus


The first and only outbreak of EI in Australia occurred in 2007 in Queensland and New South Wales.

Queensland is free of equine influenza. Australia is one of the very few countries in the world to fully eradicate the disease.


Horses, donkeys, mules

Life cycle

The incubation period is only around 1-3 days (although some may be less than 24 hours). The virus survives in the environment for up to 36 hours, but is easily killed by cleaning and disinfection.

Affected animals

  • horses

Clinical signs

The main clinical signs are usually:

  • sudden increase in temperature (to between 39 and 41°C)
  • deep, dry, hacking cough
  • watery nasal discharge which may later become thick and smelly.

Other signs can include depression, loss of appetite, laboured breathing, muscle pain and stiffness.


While the disease is rarely fatal, complications such as pneumonia are common, causing long-term debility of horses and sometimes death, especially in foals. Recovery usually occurs after a couple of weeks but horses need to be rested for a further period to avoid complications.

How it is spread

EI is rapidly spread through close direct contact between horses. Infected horses excrete the virus in their nose and mouth for up to 14 days after initial infection. Coughing contributes to the spread.

Infection can also be spread via clothing, horse equipment, people, buildings that have recently housed sick horses, vehicles, floats, grooming and veterinary instruments. Anything that comes into contact with an infected horse should be carefully and thoroughly cleaned and disinfected.

Risk period

Infection spread is most likely to occur when horses are gathered together.


Humans do not get infected with EI. Humans can physically carry the virus on their skin, hair, clothing and shoes, and can therefore transfer the virus to other horses. It is vital that you shower and wash carefully, wash your hair and put on a completely fresh set of clothes (including shoes) after contact with any horses (including your own horses) that might be infected. The virus can also be physically carried on equipment and vehicles.


Infected animals are subject to movement restrictions in order to prevent spread of the disease.

Further information

  • Learn more about equine influenza on the New South Wales Department of Primary Industries website.
  • Read about equine influenza on the Australian Government's Department of Agriculture, Fisheries and Forestry website.