On December 24, 2025, the NVWA received a report about two sick cats. One of these cats tested positive for avian influenza and died two days later, read the parliamentary letter here. Following this report, source and contact investigations were conducted by the NVWA. The investigation showed that the cat came from a dairy farm.
On January 15, the dairy cattle on that farm were screened with a sample test. At that time, no animals were sick. Research of milk samples by Wageningen Bioveterinary Research showed no active virus was present. Antibody presence was also investigated. Antibodies were found in the milk samples of one cow, indicating a past infection with the virus in that cow.
On January 22, the NVWA revisited the farm. Blood and milk samples were taken from all present cattle. These showed no avian influenza virus on the farm. Results of antibody tests are expected next week to determine if more animals have been exposed to the virus. Other mammals on the farm, such as dogs, cats, and horses, currently show no signs of illness. The people on the farm and the veterinarian are being tested by the GGD.
Antibodies against avian influenza have, as far as known, not been previously detected in dairy cattle in Europe. However, there have been many outbreaks among dairy cattle in the United States. Individual infection of a dairy cow with avian influenza virus can occur. It is important to know if this leads to spread within and between farms. There are no indications this has happened.
Milk Safety
The risk that the avian influenza virus H5N1 circulating in Europe transmits from animals to humans is very small. The risk of humans contracting avian influenza from eating chicken, eggs, beef, or milk products is also very small. Eggs, meat, and milk meet strict standards. Milk products are heated to kill viruses. Moreover, milk from the previously infected cow was removed and not used for human consumption. It is important not to consume raw milk products from a cow infected with avian influenza.
The avian influenza situation in the Netherlands remains concerning. The situation is closely monitored and all involved parties are asked to remain alert for possible signals.