DOI: 10.2807/1560-7917.es.2026.31.25.2600464 ISSN: 1560-7917
Detection of antibodies against avian influenza in European dairy cattle, the Netherlands, January 2026
Monika Z Ballmann, Luca Bordes, Kim M Bouwman, Marc Y Engelsma, Sandra Venema-Kemper, Sylvia BE Pritz-Verschuren, Rene Heutink, Marit Roose, Marcel AH Spierenburg, Arco van der Spek, Hendrik IJ Roest, Evelien A GermeraadIn December 2025, highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b genotype DI.2.1 virus was detected in a cat living on a dairy cattle farm. Milk and serum samples from the dairy cattle were tested for avian influenza virus. No viral RNA was detected; however, H5N1-specific antibodies were identified in serum samples from 34 (47.2%) of 72 lactating dairy cows and 24 (63.2%) of 38 youngstock. These demonstrate expansion of the mammalian host range of HPAI H5N1 in Europe.