H5 bird flu (avian influenza) is a serious viral disease that primarily affects birds but can also infect mammals.
Globally, more than 60 mammalian species have been infected with H5 bird flu, mainly marine mammals and bird-eating scavengers, but the virus has also been detected in dairy cattle, pet cats, goats, alpacas, pigs, horses, zoo animals and other wild animals.
Cattle
- H5 bird flu infection or disease in beef cattle herds globally has not been reported.
- In 2024, the US reported the spread of H5 bird flu from wild birds to a dairy herd; subsequently, the virus spread to other cows and herds across the US via movements of infected cows and contaminated milk, equipment, vehicles and workers spreading the virus due to poor hygiene and biosecurity practices in an intensive production system.
- Clinical signs reported in US dairy cows are generally mild, and include lethargy, fever, low appetite, nasal discharge, reduced milk production and mastitis. Most cows recover, with mortality/cull rates of 2% or less; significant disease in calves has not been reported.
- Several cases of H5 bird flu in US dairy workers and cats on infected farms exposed to unpasteurised, infected milk have been reported.
- Widespread outbreaks of H5 bird flu in dairy industries in countries other than the US have not been reported.
- The Australian dairy industry is preparing for the possibility that an H5 bird flu incursion impacts dairy herds. Strategies implemented in the US have been reviewed and adapted for the Australian industry to help minimise potential impacts of H5 bird flu on the dairy industry.
Other livestock and farm species
- Sheep, pigs, horses: global trends indicate these species are at low risk of H5 bird flu infection, severe disease and mortality.
- Dogs: reported H5 bird flu infections in dogs globally have been rare, however hunting dogs that are exposed to birds or other animals infected with H5N1 may be at greater risk of infection.
- Cats and other animals that scavenge infected birds may also develop disease which, as global trends suggest, is often fatal.
While Australia remains free of the H5N1 strain currently spreading overseas, livestock producers should understand how the virus spreads, the potential impacts, and the steps they can take to prepare and protect their animals.
Potential impacts of H5 bird flu on livestock and farming
If H5N1 or another HPAI strain were to arrive in Australia, it could affect livestock and agricultural operations in several ways:
- while bird flu mainly affects birds, recent international detections show that some mammals, including dairy cattle, can become infected
- symptoms in mammals can include fever, reduced appetite, respiratory signs (coughing, nasal discharge), and a drop in milk production in dairy animals
- infection in mammals usually results from contact with infected birds or contaminated materials.
How bird flu could reach livestock properties
Bird flu viruses spread easily through:
- direct contact with infected birds (especially waterfowl or seabirds)
- indirect contact via contaminated feed, water, bedding, vehicles, footwear, clothing or equipment
- windborne particles of dust, feathers or manure
- domestic pets or wildlife that scavenge infected carcasses.
Livestock, particularly dairy cattle and pigs, can be exposed when:
- poultry or wild birds share the same paddocks, sheds, feed or water
- farm workers or equipment move between bird and livestock areas without cleaning and disinfection.
Signs to watch for in livestock
Although infections in livestock are generally rare, animal owners should stay alert for unusual signs such as:
- sudden drop in feed intake or milk yield
- coughing, nasal discharge or breathing difficulties
- fever or depression
- nervous signs (unsteady movement, tremors)
- unexplained illness or deaths in multiple animals
If you notice these symptoms, contact your Local Land Services veterinarian or call the Emergency Animal Disease Hotline on 1800 675 888 immediately.
How to prepare and prevent bird flu on your property
Farmers and those keeping animals should be prepared by using good biosecurity practices and monitoring the health of their livestock.
You can reduce the risk of pests and diseases by:
- keeping poultry and waterfowl separate from other livestock
- providing dedicated feed and water sources that wild birds cannot access
- cleaning and disinfect equipment, vehicles and clothing before moving between bird and livestock areas
- using footbaths and handwashing stations at shed or yard entrances
- storing feed securely to prevent contamination by wild birds or rodents
- reducing standing water around sheds and yards
- keeping livestock away from areas where wild birds gather
- fencing off dams or ponds that attract waterfowl
- recording visitors and vehicle entry to your propert.
- allowing only essential personnel into livestock or poultry areas
- using dedicated tools and protective clothing for different species
- observing all animals daily for changes in behaviour, appetite or productivity
- reporting any sudden or unusual deaths immediately
- working with your veterinarian to maintain regular health checks.
Biosecurity measures for grazing near wetlands
Minimise livestock contact with wild birds
- Avoid grazing livestock on wetlands or floodplains heavily populated by water birds when possible
- Fence off or restrict access to high-density bird areas where feasible.
Monitor and report
- Report 5 or more sick or dead wild birds OR 1 or more sick or dead pelicans, birds of prey, black swans or marine mammals in wetlands or coastal areas to the Emergency Animal Disease (EAD) hotline on1800 675 888
- Watch for unusual behaviour or illness in any livestock or wildlife
- If you notice any unusual signs of disease, unusual behaviour or unexplained deaths or illness in livestock or wildlife, call the EAD hotline on 1800 675 888, contact your veterinarian, or call your Local Land Services (LLS) District Vet on 1300 295 799.
Enhanced farm biosecurity
- Isolate new or returning animals to wetlands for at least 30 days
- Clean and disinfect vehicles, equipment and footwear before entering grazing areas
- Maintain visitor and livestock movement records and prepare your Biosecurity Management Plan
Feed, water and equipment management
- Where possible, restrict wild bird access to supplementary feed or water troughs to prevent contamination
- Regularly clean troughs, feeding and hunting equipment to prevent disease spread.
More information
WHA - Wildlife Health Australia
Resources
H5 bird flu resources, including factsheets, posters and signs are available here