Avian influenza antibodies have been detected in a dairy cow at a dairy farm in the Netherlands, the country’s Ministry of Agriculture, Fisheries, Food Security and Nature announced on January 23.
This is the first reported case of avian influenza antibodies in a cow in Europe.
The cow was on a farm in the municipality of Noardeast-Fryslân, province of Friesland. No evidence of active viral circulation of avian influenza among the dairy cows on this farm has been found. There are also no signs of avian influenza spreading to other dairy farms.
On December 24, 2025, the Netherlands Food and Consumer Product Safety Authority (NVWA) received a report of two sick cats. One of these cats tested positive for avian influenza and died two days later. After this report, the NVWA conducted source and contact tracing. This investigation revealed that the cat came from a dairy farm.
On January 15, the dairy cattle on that farm were screened with a random sample. There were no sick animals present at that time. Analysis of the milk samples by Wageningen Bioveterinary Research revealed that no active virus was present. The presence of antibodies was also tested, which was found in the milk samples from one cow. This indicates a previous infection with the virus in that cow.
The NVWA visited the farm again on January 22. Blood and milk samples were taken from all cattle present. These showed there was no avian influenza virus on the farm. The results of the antibody tests are expected this week and will indicate whether more animals have come into contact with the virus. Other mammals on the farm, such as dogs, cats and horses, have not shown any symptoms. The people on the farm and the veterinarian are being tested by the Municipal Health Service (GGD).
Inquiries by the NVWA indicate that the affected cow showed symptoms in mid-December consistent with an avian influenza infection. The cow had mastitis and a reduced milk yield. The cow has since fully recovered.
Antibodies against avian influenza are not previously known to have been found in dairy cattle in Europe. However, there have been numerous avian influenza outbreaks among dairy cattle in the United States. Individual infection of a dairy cow with the avian influenza virus can occur. It is important to know whether this leads to spread within and between farms. There is no evidence that this has occurred.
