H5N1 updates put cats back at the center of surveillance
CURRENT BRIEF VERSION: A pair of H5N1 developments is sharpening concern for companion animal and livestock surveillance. In Washington state, an outdoor cat tested positive for H5N1 after presumed exposure to wild birds, underscoring that cats remain vulnerable to spillover outside of raw-food-linked cases. In the Netherlands, follow-up testing on a Friesland dairy farm linked to a fatal feline case found H5N1 antibodies in five cows, expanding from an earlier report of one seropositive cow. Dutch authorities said they found no evidence of active viral circulation in the herd, and Wageningen researchers noted no virus particles were detected in the affected cow or its milk, suggesting past exposure rather than an active dairy-cattle outbreak like the one seen in the U.S. (wormsandgermsblog.com)
Why it matters: For veterinary professionals, the update reinforces two practical points: cats can still be sentinels for H5N1 exposure, and cattle investigations may begin with a feline case rather than obvious herd illness. That matters because cats appear highly susceptible to severe disease; a 2025 systematic review found a 71.3% case fatality rate among reported RT-PCR-confirmed feline avian influenza infections, with respiratory and neurologic illness most common, and some cats infected without obvious clinical signs. International Cat Care noted that reported feline cases, especially H5N1, have risen sharply since 2023, most often after bird-to-cat transmission through predation, scavenging, contaminated raw poultry, or raw milk from infected cattle. Diagnostic vigilance is especially important in cats with outdoor access, farm exposure, contact with sick or dead birds, or consumption of raw meat or raw milk. Cornell advises considering H5N1 PCR testing in neurologic cats and those with compatible exposure histories. (pmc.ncbi.nlm.nih.gov)
What to watch: Watch for any additional Dutch herd findings, and for whether U.S. and European veterinary authorities further broaden guidance on testing cats as part of H5N1 surveillance. The practical prevention message is also getting clearer: avoid raw poultry and unpasteurized milk, keep farm cats from drinking on-farm milk, and reduce opportunities for hunting or scavenging of wild birds. (nvwa.nl)