First Detection of Avian Influenza Antibodies in European Dairy Cattle
Authorities in the Netherlands have confirmed the presence of avian influenza (H5N1) antibodies in a dairy cow in the municipality of Noardeast-Fryslân. This represents the first known instance of a dairy cow in Europe testing positive for antibodies to the virus, following widespread outbreaks in the United States throughout 2024 and 2025.
The investigation was triggered following a report to the Netherlands Food and Consumer Product Safety Authority (NVWA) on December 24, 2025, regarding two sick cats. One of the cats tested positive for avian influenza and subsequently died. Contact tracing revealed that the deceased feline originated from a dairy farm, prompting a thorough screening of the resident livestock. Initial screenings conducted on January 15 revealed that while no active virus was detectable via PCR testing in the individual milk samples or the bulk tank, one cow tested positive for H5N1 antibodies. The presence of these antibodies indicates a past infection. Medical records for the cow showed it had suffered from respiratory issues and mastitis in December, symptoms consistent with avian influenza infection in cattle.
On January 22, the NVWA conducted follow-up testing on all cattle at the facility. Results released on January 23 confirm that there is currently no active viral circulation on the farm. All recent milk and blood samples tested negative for the active virus, though five samples are being re-tested due to laboratory errors. Dogs, horses, and other cats on the farm currently show no symptoms. The Municipal Health Service (GGD) is testing farm workers and the attending veterinarian as a precaution.
