Antibodies of the bird flu virus have been found in a dairy cow at a dairy farm in the municipality of Noardeast-Fryslan in the province of Friesland. No indications were found of active virus circulation of the bird flu virus among the dairy cows on this farm. There are also no signs of the spread of bird flu at other dairy farms.

On December 24, 2025, the NVWA received a report about two sick cats. 1 of these cats tested positive for bird flu and died 2 days later, Read the letter to parliament here. In response to this report, source and contact research was carried out by the NVWA. That investigation showed that the cat came from a dairy farm.

On 15 January, the dairy cattle on that farm were screened with a random sample. There were no sick animals present at that time. Examination of the milk samples by Wageningen Bioveterinary Research showed that no active virus was present. Research has also been done into the presence of antibodies. These were found in the milk samples of 1 cow. This indicates a past infection with the virus in that cow.

The NVWA visited the company again on 22 January. Blood and milk samples were taken from all cattle present. This showed that there is no bird flu virus on the farm. The results of the antibody tests are expected next week. This way we know whether more animals have been in contact with the virus. Other mammals on the farm, such as dogs, cats and horses, have no symptoms at the moment and in the past period. The people on the farm and the veterinarian are tested by the GGD.

As far as is known, antibodies against bird flu have not previously been demonstrated in dairy cattle in Europe. However, there have been many outbreaks of bird flu among dairy cattle in the United States. An individual infection of a dairy cow with bird flu virus can occur. It is important to know whether this leads to spread within and between companies. There are no indications that this has happened.

Milk safety
The risk of the bird flu virus H5N1, which is prevalent in Europe, transmitting from animals to humans is very small. The risk of people contracting bird flu by eating chicken, eggs or beef, or through dairy products, is also very small. Eggs, meat and milk meet strict requirements. Dairy products, for example, are heated in such a way that viruses die. Moreover, the milk from the previously infected cow has not been processed for human consumption due to the existing mastitis picture. However, it is important not to consume raw milk products from a cow infected with bird flu.

The bird flu situation in the Netherlands remains worrying. The situation is being closely monitored and all those involved have been asked to remain alert to possible signals.