About H5N1 bird flu
H5 bird flu is a viral disease of birds that is found globally. Virus strains are described as low pathogenicity (LPAI) or high pathogenicity (HPAI).
Australia has responded to outbreaks of high pathogenicity avian influenza outbreaks in poultry in the past, including H7 outbreaks in Victoria and interstate. Since 1976, there have been 13 outbreaks of high pathogenicity bird flu on poultry farms in Australia. These have occurred in Victoria, Queensland, New South Wales and the ACT, including more recent H7 outbreaks in 2020, 2024 and 2025.
H5 bird flu has now been confirmed in Western Australia, South Australia and New South Wales. Response and surveillance activities are under way, and the situation may change as further information becomes available.
High pathogenicity H5 bird flu differs from other bird flu strains and has caused mass mortalities in poultry and many wild birds overseas. It can also affect some mammals.
H5 bird flu:
- spreads more easily than other bird flu strains
- can kill large numbers of wild birds
- has no effective treatment
- usually leads to poor outcomes for infected birds and mammals.
As H5 bird flu is spreading globally and has now been confirmed in Australia, early reporting of sick or dead wild birds and wildlife is important. If the virus spreads further, it may infect wild birds and other native animals.
Signs of bird flu
Keep watch for signs of bird flu.
Wild birds
- can’t stand, walk, or fly properly
- droopy or puffed-up appearance
- breathing problems (panting or sneezing)
- unusual head or neck posture
- sudden death (especially in large numbers)
Poultry (chickens, ducks, etc.)
The first sign of bird flu may be the sudden death of some poultry. Other signs include:
- rapid drop in feed intake
- sudden drop in egg production
- typical ‘sick bird’ signs - ruffled feathers, depression, closed eyes
- diarrhoea
- birds having trouble breathing, coughing or sneezing
- lethargy or not eating/drinking
- swelling around the head, neck and eyes
- discharge from the eyes (conjunctivitis)
- twisted necks or unusual posture.
H5 bird flu should be considered if a high proportion of a flock or group of birds becomes ill very quickly – progressing from normal to severe illness or death within 24-28 hours.