Bird flu: Everything you need to know about avian influenza

What is bird flu?

Bird flu, also known as avian influenza, is a serious and highly contagious viral disease affecting wild, farmed and pet animals. It can cause severe illness and death in many species.

It can infect bird and mammal species, including humans, livestock and wildlife. This includes marine mammals such as seals, sea lions and dolphins.

There are numerous bird flu subtypes but the H5N1 (clade 2.3.4.4b) strain has been the most predominant since its emergence in 2021.

What is the current situation?

Australia is the only continent free from the H5N1 bird flu strain.

Outbreaks of the H7 bird flu strain declared in Victoria, New South Wales and Australian Capital Territory in 2024 were eradicated.

A further H7 strain was detected in Victoria in February 2025 and is being managed.

These H7 bird flu outbreaks have been in poultry and have not involved any parts of South Australia.

What if there is an H5 bird flu outbreak in Australia?

Overseas outbreaks show H5 bird flu would likely have significant effects on our unique wildlife – including bird species and marine mammals – and the agriculture industry, especially poultry.

It is not only threatened species, such as Australian sea lions, expected to be affected by H5 bird flu, but also those considered common and abundant, for example black swans might be susceptible.

H5 bird flu cannot be prevented from arriving and, in many cases, wildlife mass mortality events are unable to be stopped.

What is being done to prepare for an H5 bird flu outbreak?

The Australian Government is working with state and territory governments, animal and wildlife health organisations, industry groups and the non-government sector.

Within South Australia, location-specific planning is being undertaken in key areas, including national parks, such as Seal Bay Conservation Park and Coorong National Park.

Assessments are being undertaken to help understand which native species in South Australia are likely to be susceptible to H5 bird flu and whether any conservation actions can support the species if the disease arrives.

What is the situation overseas?

H5 bird flu has infected more than 500 wild bird species and more than 80 mammalian species.

Mass mortalities have been recorded in sea lions, elephant seals, tigers, lions, cheetahs, black-browned albatrosses, Eurasian cranes and red knots.

How does bird flu spread?

There are numerous factors that can contribute to the spread of bird flu but the most common is the movement of infected wild birds, particularly along migratory routes.

Migratory wild birds can carry H5 bird flu long distances and makes them a potential pathway for the disease to enter Australia.

Bird flu can also spread through other wild animals, poultry and humans. Human infections are rare and people with bird flu may have no, or mild, symptoms.

How can I reduce the spread of bird flu?

Bird keepers and wildlife carers should implement a biosecurity plan, including using hygiene measures and personal protective equipment (PPE) when handling sick or injured birds or other animals.

Injured or sick birds in care should not be kept with any pet birds, aviaries and animal handling equipment should be kept clean and always wash hands with soap before and after handling birds.

What are signs of the disease in birds?

Bird flu can be confused with many other diseases that have similar clinical signs. The infection can vary in severity, including:

• Sudden death in several birds in a short space of time
• Respiratory distress, including open mouth breathing, coughing, sneezing
• Neurological signs, including twisted neck, inability to stay upright, inability to fly, uncoordinated movement, walking or swimming in circles, partial or full paralysis
• Swollen head
• Reluctance to move, eat or drink
• Reduced egg production
• Misshapen eggs
• Diarrhoea
• Droopy appearance

What are signs of the disease in mammals?

Infected wild mammals may show numerous clinical signs, including:

• Incoordination and tremors
• Seizures
• Difficulty breathing
• Nasal discharge or drooling
• Death, including the potential for mass mortality events

What should I do if I see a sick or dead bird?

You should avoid contact with sick or dead birds, keep pets away, and record relevant details, including date, time, location, species and numbers.

Report observations to the Emergency Animal Disease Hotline on 1800 675 888 – 24 hours a day, 7 days a week – or contact your local veterinarian if you find:

• 1 or more sick or dead waterfowl (ducks, geese, swans), shorebirds (stilts, avocets), seabirds or predatory and scavenging species in the same place.

• 5 or more sick or dead wild birds of any other species in the same place.