Avian influenza in cattle in the Netherlands

How it all began

A cow screening on the farm was initiated after a cat living on the property was confirmed to be infected with the avian influenza virus

. This raised concerns that the virus could have spread to other animals, including cows. The Dutch Food and Consumer Product Safety Authority (NVWA) decided to conduct testing, collecting milk samples from 20 cows and examining the animals themselves. Laboratory testing

Laboratory testing results conducted at the Wageningen Bioveterinary Center (WBVR) showed that the H5N1 virus was not detected in any of the cows. However, one cow tested positive for antibodies to the virus, indicating that the animal had previously contracted the disease. Importantly, this cow had exhibited symptoms of mastitis and decreased milk yield in mid-December, but she fully recovered, and her milk

did not enter the food chain at that time. Additional measures and checks

After antibodies were detected in the cow, samples were taken from all the other cows on the farm. Tests conducted on January 23 confirmed the absence of active virus in all animals tested. "All samples tested negative. This means the animals do not have active virus," said Monika Ballmann, a WBVR researcher and head of the Dutch National Reference Laboratory for Avian Influenza.

Meanwhile, antibody testing of samples is ongoing, with results expected in the coming days. As a precaution, the farm has implemented restrictions: all milk is being pasteurized, which ensures virus inactivation and protects consumers.

Why this case is important:

The detection of antibodies to the H5N1 virus in a cow in the Netherlands is important for understanding the spread of the virus. Previously, cases of cattle infection had only been recorded in the United States , where, by the end of January 2026, 1,084 cases had been reported on dairy farms in 19 states. The most recent outbreak in the United States was recorded on December 13, 2025 , in Wisconsin.

The virus's expanding geographic distribution raises questions about its potential threat to other animal species and, possibly, humans. It's important to note that regulators currently state there is no threat to consumers, and measures taken on farms are aimed at preventing further spread of the virus.

Avian influenza in cattleIn the Netherlands, this discovery highlights the need for continuous monitoring of zoonotic diseases and preparedness to respond to such incidents. This discovery poses new challenges for veterinarians, epidemiologists, and regulators, who must work together to minimize risks and protect both animals and people. It is crucial to continue research and information sharing to understand how viruses can adapt and spread in new environments.