Protecting Dairies: Lessons from Bird Flu
Published February 8, 2026
The recent outbreak of H5 avian influenza, or H5 bird flu, in US dairy cattle has underscored the importance of vigilance among Australian farmers. This global health concern, which affects bird species, wildlife, and potentially livestock, has already caused significant challenges in the US dairy industry.
The virus was first detected in US dairy cattle in 2024, leading to illness, production losses, and even sickness among dairy farm workers. Since then, it has spread across 18 US states, impacting over 1000 dairy herds.
The unique transmission from birds to dairy cows has provided valuable insights into the disease's behavior in cattle and its potential spread within dairy systems. Despite this, Australia remains free from this strain of H5 bird flu, and the risk to the Australian dairy industry is considered low.
However, the US experience serves as a valuable lesson for preparedness. The Federal Government, in collaboration with states, territories, and the industry, has taken proactive measures to strengthen national preparedness. This includes enhanced surveillance, improved coordination between animal, wildlife, and human health agencies, and targeted investments.
For the dairy sector, the Department of Agriculture, Fisheries, and Forestry, supported by Dairy Australia, commissioned an independent risk assessment. This assessment aimed to understand the potential impact of a spillover event under Australian conditions. The findings, shared during a Dairy Australia-led webinar, offered a clear, evidence-based perspective on risk and preparedness for Australian farms.
The assessment revealed that the risk of H5 bird flu entering the Australian dairy herd is low, and even if it does occur, the risk of spread between farms is also low. This lower risk can be attributed to factors such as lower farm density and reduced routine cattle movements. Australia's proactive approach, coupled with these factors, provides a significant advantage.
In the event of H5 bird flu reaching Australia through bird migration, dairy farmers should be vigilant and watch for clinical signs. In infected US herds, common indicators included a sudden drop in milk production, thick milk resembling severe mastitis, fever, and lethargy. While mortality rates in cattle have been low, morbidity has been high, with many cows requiring weeks or months to recover their production levels.
Prevention measures for the Australian industry include:
- Animal Movements: Implementing quarantine and observation periods for purchased animals or inter-farm movements can reduce exposure. Testing protocols for cattle movements and bulk-milk screening have also been introduced in the US.
- Milking Hygiene: Maintaining high standards of milking hygiene is crucial, especially in infected herds. Milking affected or suspect cows last or separately can help limit the spread through liners and cups.
- Mastitis Management: Careful handling of mastitic milk, proper equipment cleaning, and consistent teat preparation are essential.
- Reducing Milk Aerosols: Lowering the risk of milk aerosols or airborne droplets is a practical step. High-pressure hosing of milk spills should be avoided, as it can create fine aerosols. Instead, lower-pressure wash-down methods and minimizing splash help reduce exposure.
- People Protection: Good biosecurity practices include wearing gloves during milking and handling milk or sick animals, washing hands after glove removal, and managing contaminated work clothing. Encouraging seasonal flu vaccination can also reduce the rare possibility of dual infections.
- Surveillance and Early Advice: Farmers should trust their instincts and seek early advice if they notice unusual clusters of mastitis-like illness, sudden production drops, or unexplained bird deaths.
Ultimately, preparedness in the dairy industry relies on fundamental principles. A well-maintained, up-to-date biosecurity plan remains the cornerstone of effective prevention and control measures.
- Andy Hancock, Dairy Australia
Updated February 8, 2026 3:00 pm | a few seconds ago
