The information and links on this page give you access to the latest advice from key agencies about Hendra virus.
Since 1994, Hendra virus (HeV) has been the cause of death in over 100 horses. Most cases have been the result of spillover infection from flying-foxes. Others have been the result of direct transmission from infected horses. To date, all cases have occurred in Queensland (Qld) and New South Wales (NSW).
Hendra virus research helps us learn more about the virus and the disease it causes. It also informs the steps we can take to reduce the risk of infection.
New Hendra virus variant
A retrospective study has identified a variant of Hendra virus. The sample used for the study was from a horse euthanased in Queensland in 2015. Evidence of this variant virus, designated HeV-g2, was found in grey-headed flying-foxes from Victoria and South Australia. These findings show that all areas in Australia where flying-foxes and horses co-exist are at risk of Hendra virus spillover.
In October 2021 a horse infected with Hendra virus variant (HeV-g2) was detected in the Newcastle area of NSW. The horse showed severe illness consistent with the original Hendra virus, and was euthanased. This was the first NSW horse to test positive to Hendra virus outside of northern area of the State.
Prevention and biosecurity
A registered Hendra virus vaccine is available for horses. Vaccinating horses is the most effective way to help manage Hendra virus disease (including the Hendra virus variant HeV-g2). Vaccinated horses also reduce the risk of Hendra virus transmission to people and susceptible animals including dogs.
Diagnostic tests and processes in Australian states and territories have been updated to ensure that all known Hendra virus variants can be detected.
Additional prevention measures
It is important for all horse owners and carers to use good hygiene and biosecurity practices regardless of where they are located.
To help prevent Hendra virus in horses, reduce the opportunity for flying-foxes and horses to interact. Do this by removing feed bins and water troughs from under or near trees. Remove horses or restrict their access to paddocks where flowering or fruiting trees attract flying-foxes.
When working with or around horses, particularly those showing signs of illness or lethargy, practice good hygiene:
- wash your hands regularly
- cover any cuts or wounds with a water-resistant dressing
- use appropriate personal protective equipment when handling sick horses
- clean and disinfect equipment that has been in contact with a horse's body fluids.
Identifying sick horses
Hendra virus can cause a broad range of signs in horses. Hendra virus infection should be considered in any sick horse when the cause of illness is unknown and particularly where signs progress quickly with rapid deterioration.
The following signs have all been associated with Hendra virus cases in horses, but not necessarily all signs will be found in any one infected horse:
- rapid onset of illness
- increased heart rate
- discomfort or weight shifting between legs
- rapid deterioration with either respiratory and/or nervous signs.
Respiratory signs include:
- difficulty breathing
- rapid breathing
- nasal discharge at death - can be initially clear, progressing to stable white froth or stable blood-stained froth.
Nervous signs include:
- wobbly gait
- apparent loss of vision in one or both eyes
- aimless walking in a dazed state
- head tilting and circling
- muscle twitching
- urinary incontinence
- inability to rise.
Sick horses must not be moved from their location and should be isolated from other animals on the property.
Report sick horses
Contact a vet if you see any of the signs listed above in your horse. All suspect cases of Hendra virus must be reported to your state or territory department responsible for biosecurity. You or your vet can report suspect horses by calling the national Emergency Animal Disease Watch Hotline on 1800 675 888.
About Hendra virus
Transmission of Hendra virus from an infected horse to one or more domestic horses sometimes occurs, usually through very close contact. A small number of people have been infected with the virus, from infected horses. Tragically 4 of the 7 people who were infected have died. Five of these people were veterinary health professionals.
Hendra virus and its relationship with flying-foxes
Flying-foxes (also called fruit bats) are a natural host of Hendra virus, although they do not show any apparent signs of illness when infected. There are 4 species of flying-fox on mainland Australia:
- black flying-fox
- spectacled flying-fox
- little red flying-fox
- grey-headed flying-fox.
Hendra virus has been found in all 4 species.
Horses can be infected with the virus when they come into contact with the flying-fox’s urine and faeces. This is why it is important to keep feed and water bins away from under or near trees. Infection can also occur through contact with flying-fox saliva - such as the horse eating or coming into contact with partially chewed fruit or flowers.
Flying-foxes are a protected species. They are critical to our environment because they pollinate our native trees and spread seeds. Without flying-foxes we would not have our eucalypt forests and rainforests.
Wildlife Health Australia has further advice about handling bats.
You can get more information about Hendra virus and related research by using the following links.
- Queensland Department of Agriculture and Fisheries
- NSW Department of Primary Industries
- Australian Government Department of Agriculture, Water and the Environment
- CSIRO’s Australian Centre for Disease Preparedness
- Novel Hendra virus variant detected by sentinel surveillance of Australian horses
- Farm Biosecurity
- AUSVETPLAN: Hendra virus response policy and technical information