High Pathogenicity Avian Influenza

Page updated 26 November 2025

AVA HPAI Resources Launched in November 2025

The AVA have developed several resources in November 2025 to assist veterinary preparation and response to HPAI. These include:

AVA Policy – High Pathogenicity Avian Influenza in pet birds, backyard poultry and wild birds. This policy provides a basis for advocacy to governments about HPAI preparedness and response strategies impacting private veterinary practitioners who work with aviculture, pet birds, backyard poultry and wild birds. Cases of this nature differ from commercial poultry and require alternative management and control measures.
AVA High Pathogenicity Avian Influenza Private Veterinary Practitioner Preparedness Toolkit. This toolkit provides brief guidance and checklists to assist veterinarians and veterinary practices prepare and respond to suspected HPAI cases in wildlife, pet birds, and backyard poultry.
AVA Public Education Poster/Flyer – H5N1 Bird Flu: High Pathogenicity Avian Influenza.
A public education resource for veterinary practices to education clients on what to do if they see a sick or dead bird (wild, pet bird, poultry)

Background HPAI

Avian influenza is a global viral disease of birds and there are many strains of the virus that cause infections of differing severity, and all bird species are considered vulnerable to avian influenza. High pathogenicity avian influenza (HPAI) viruses are associated with severe disease and high mortality in poultry. HPAI H5N1 clade 2.3.4.4b is the predominant strain causing recent outbreaks globally.

Australia has successfully contained and eradicated H7 HPAI in poultry several times in the last 50 years, including the outbreaks in 2024 in Victoria, New South Wales and the Australian Capital Territory.
Australia and New Zealand currently remain free from the H5N1 strain of avian influenza.

Avian influenza viruses (both low pathogenicity and high pathogenicity strains) have also been known to infect other animal species overseas. Spill over infections of the H5N1 strain of HPAI virus in non-avian animal species such as humans, pigs, cattle, sheep, goats, marine animals, domestic dogs and cats, foxes, ferrets, and tigers and leopards have been reported in some countries.

The 2024 outbreaks of HPAI H7 in New South Wales, the Australian Capital Territory, and Victoria have now been successfully resolved (further information below). However, ongoing outbreaks of H5N1 globally have increased Australia’s level of risk for incursions of HPAI viruses of global concern. Migratory birds returning to Australian shores annually between September and November may introduce HPAI viruses.

Avian influenza is a national notifiable emergency animal disease (EAD) and any unusual bird deaths must be reported to the Emergency Animal Disease Hotline on 1800 675 888. This number will connect you with your state or territory’s department of primary industries or agriculture.

Zoonotic disease

Avian influenza is a zoonotic disease and is potentially fatal to humans. The disease can be passed from birds to humans who are in close contact with poultry or other birds. In Australia, there is minimal risk of people being affected by avian influenza viruses through normal contact with healthy birds, however it is important to always practice good personal hygiene when handling birds.

For more information about avian influenza in humans, visit the Department of Health and Aged Care website:
https://www.health.gov.au/diseases/avian-influenza-in-humans-bird-flu

Good biosecurity practices are the key to preventing the spread of avian influenza in poultry species and are critical in combating any incursion.
The following information about bird biosecurity is a valuable resource to make clients aware of:
https://www.agriculture.gov.au/biosecurity-trade/pests-diseases-weeds/protect-animal-plant/bird-owners

Key information about the clinical signs

The clinical signs of avian influenza in birds are variable and depend on a range of factors including the virulence of the virus, the species and age of the birds infected, the presence of concurrent diseases, and the environment. In severe forms, such as H5N1 infection, the disease appears suddenly and birds die quickly.

HPAI should be considered as a differential diagnosis in the following scenarios for wild birds:

Small groups or clusters (5 or more) of sick or dead wild birds of any species.
Individual or <5 sick or dead wild birds:
- seabirds, waterbirds, shorebirds or birds of prey
- any other bird species with signs of avian influenza infection as outlined below.

Infected live birds may show a wide range of clinical signs, including:

Wildlife: Presence of dead birds, neurological signs (e.g. ataxia, tremors, seizures), swelling/cyanosis of head or legs, respiratory distress
Pet birds and backyard poultry: Sudden death, lethargy, inappetence, reduced egg production, swelling/cyanosis of head or legs, respiratory distress (e.g., nasal discharge, dyspnoea), neurological signs (e.g., tremors, ataxia, seizures), gastrointestinal issues (e.g., vomiting, diarrhoea) and petechial haemorrhaging.

Some species may be asymptomatic or show only very mild clinical signs. In some cases, birds may die suddenly without displaying any clinical signs.