H5 bird flu detected in WA: what to know

Despite the Australian Government’s confirmation that Australia has recorded its first detection of the H5N1 strain of avian influenza (H5 bird flu) in two wild sea birds in south-west Western Australia, industry experts are reminding farmers the risk for Australian dairy herds is considered low.

At this stage, the virus has only been found in two birds in Western Australia. There is currently no evidence of infection in any Australian wildlife or poultry. The risk to dairy cattle is still considered low, and there are no impacts on milk production or supply. H5 bird flu also remains a low risk to public health, with human infections rare.

A joint risk assessment undertaken by the Australian Government Department of Agriculture, Fisheries and Forestry (DAFF) and Dairy Australia completed in 2025 found the likelihood of H5 Bird Flu spreading from wild birds to Australian dairy cattle to be low, reflecting Australia's geography, farming systems and existing biosecurity measures.

While Australia is the last continent to have H5 Bird Flu detected, only one country has had cases of it infecting dairy cattle. Since first being detected in dairy herds in the United States in 2024, the virus has been identified on hundreds of dairy farms, resulting in animal health impacts, reduced milk production and significant operational challenges. These experiences reinforce the importance of maintaining strong biosecurity measures and taking a cautious approach.  However, the United States remains the only country to record transmission to dairy cattle to date.

Dairy Australia, Australian Dairy Farmers and the Australian Dairy Products Federation are working together with federal and state government agencies to monitor the situation and are prepared to act as required.

As always, dairy farms are encouraged to maintain and strengthen their biosecurity practices as the best defence. All dairy farms are encouraged to:

• Review and update their existing farm biosecurity plans.
• Make sure current hygiene and biosecurity practices are followed every day by anyone who comes on-farm.
• Continue to keep a close eye on herd health and watch for unusual signs.

Symptoms reported in infected US cattle include a drop in milk production, loss of appetite, lethargy, abnormal or thickened milk and fever.

If farmers notice anything unusual in their herd or local wildlife they should immediately contact their vet or call the Emergency Animal Disease Hotline on 1800 675 888.

For more information and resources visit Dairy Australia's Emergency animal diseases