Imagine a world where dairy farms are under threat from an unexpected enemy - bird flu. It's a scenario that's already played out in the US, and it's a wake-up call for Australian farmers to stay alert and prepared.
The H5 avian influenza, or H5 bird flu, has caused quite a stir, impacting bird species, wildlife, and even livestock. An outbreak in US dairy cattle has highlighted the importance of vigilance, especially for our Australian farmers.
The virus first reared its ugly head in 2024, causing illness and production losses in US dairy herds. It spread rapidly, affecting over 1000 herds across 18 states. The movement of the virus from birds to dairy cows was unprecedented, but it provided valuable insights into the disease's behavior and its potential spread in dairy systems.
Australia has been fortunate to remain free from this strain of H5 bird flu, and the risk to our dairy industry is currently assessed as low. However, the experiences of our overseas counterparts offer valuable lessons that can guide our preparedness efforts.
In response to the evolving global situation, the Federal Government, in collaboration with states, territories, and industry, has taken proactive measures. They've strengthened national preparedness through enhanced surveillance, improved coordination between animal, wildlife, and human health agencies, and targeted investments.
For the dairy sector specifically, the Department of Agriculture, Fisheries, and Forestry, with support from Dairy Australia, commissioned an independent risk assessment. The aim was to understand the potential impact of an H5 bird flu spillover event under Australian conditions. The findings, shared with farmers and industry through a Dairy Australia-led webinar, provided a comprehensive and evidence-based view of the risks and preparedness measures needed.
The assessment revealed that the risk of H5 bird flu entering the Australian dairy herd is low, and even if it does, the risk of spread between farms is also minimal. While there's still much to learn about the factors influencing H5 bird flu spread in cattle, this lower risk is likely due to a combination of factors, including lower farm density and fewer routine cattle movements.
Australia has the advantage of being pre-warned, unlike the US, where the outbreak was unexpected and resulted in a period of uncontrolled spread before control measures could be implemented.
If H5 bird flu were to arrive in Australia via bird migration, dairy farmers should be vigilant for specific clinical signs. In infected US herds, the most consistent signs included a sudden drop in milk production, abnormal thick milk resembling severe mastitis, fever, and lethargy. While mortality rates in cattle have been low, morbidity has been high, with many cows taking weeks or even months to recover their production levels.
So, what can Australian dairy farmers do to prevent the introduction and spread of H5 bird flu?
Experience from the US outbreak has identified a few simple yet effective measures. Firstly, when it comes to animal movements, such as purchases or inter-farm transfers, quarantining and observing cows before they join the milking herd can reduce exposure. Additionally, testing protocols for cattle movements and bulk-milk screening have been implemented in the US.
Maintaining milking hygiene is critical in infected herds. Milking affected or suspect cows last or separately, where possible, can help limit the spread via liners and cups. Careful handling of mastitic milk, thorough cleaning of equipment, and consistent teat preparation are all essential practices.
Reducing milk aerosols, or airborne milk droplets, is another practical step. High-pressure hosing of milk spills can create fine aerosols, so using lower-pressure wash-down methods and minimizing splash helps reduce exposure.
Protecting the people working on the farm is also crucial. Wearing gloves during milking and when handling milk or sick animals, washing hands after glove removal, and managing contaminated work clothing are all practical biosecurity measures. Encouraging seasonal flu vaccination further reduces the rare possibility of dual infection.
Finally, surveillance relies on the keen eyes and instincts of farmers. Unusual clusters of mastitis-like illnesses, sudden production drops, or unexplained bird deaths should prompt early advice and action.
In conclusion, preparedness comes down to the fundamentals. Having a written, up-to-date biosecurity plan is the foundation of a robust defense against potential threats like H5 bird flu.
So, Australian dairy farmers, stay vigilant, stay informed, and keep those biosecurity plans sharp!
- Andy Hancock, Dairy Australia
Updated: February 08, 2026, 3:00 pm
