With the recent arrival of highly pathogenic avian influenza (HPAI) in New Zealand, the Ministry for Primary Industries (MPI) and the veterinary sector are working closely to monitor and detect the disease.
Although the risk to New Zealand dairy cattle remains very low, it is important for farmers and animal owners to understand what avian influenza is, how it spreads, and the signs to watch for.
Avian influenza, commonly known as bird flu, is a viral disease that primarily affects birds. Strains are classified into two categories:
LPAI generally causes mild disease or no obvious symptoms in affected birds.
HPAI causes severe illness and can result in high mortality rates in bird populations.
The strain recently detected in New Zealand is HPAI H5N1. First identified in 2020, this strain has caused widespread outbreaks in wild birds, poultry and marine mammals around the world.
Avian influenza spreads easily through body fluids, faeces and contaminated environments. The virus can also be transmitted through contaminated water, feed, equipment and footwear. Cool, moist conditions allow the virus to survive for extended periods in the environment.
Although H5N1 is primarily adapted to infect birds, it has demonstrated the ability to spread to other animal species. In 2024, HPAI H5N1 was detected in dairy cattle in the United States.
Affected cattle may show:
MPI currently considers the risk of HPAI infection in New Zealand dairy cattle to be very low. This is partly due to differences between New Zealand farming systems and those used in North America.
Where infection has occurred overseas, most affected dairy cattle recovered within two to three weeks with supportive care.
While the risk is low, HPAI can occasionally spread from infected animals to people.
Good hygiene practices are the best form of protection:
The virus is destroyed by cooking, meaning properly cooked poultry and eggs remain safe to eat. However, people should avoid consuming unpasteurised milk.
If you find a sick or injured bird, contact your local Vetora clinic before handling or transporting it.
Watch for:
If you see three or more sick or dead wild birds together, report them immediately to the MPI Exotic Pest and Disease Hotline:
Early reporting helps authorities monitor and respond quickly to potential outbreaks.
For advice on protecting backyard poultry and staying up to date with avian influenza information, visit the MPI website.
