H5N1 updates sharpen concern around cats and Dutch dairy cattle

H5N1’s small signals are still adding up. Two recent developments, a fatal infection in an outdoor cat in Washington state and antibody-positive dairy cows on a Dutch farm, don’t change the overall map of avian influenza overnight, but they do sharpen two ongoing concerns for veterinarians: cats continue to be highly vulnerable spillover hosts, and cattle exposure outside the U.S. is no longer theoretical. (wormsandgermsblog.com)

The Washington case appears straightforward, but important. Scott Weese reported that an outdoor cat in Washington state tested positive for H5N1 and that exposure was thought to be from contact with wild birds rather than contaminated food. A Washington State Department of Agriculture update from February 17, 2026, lists a confirmed domestic cat case with the suspected source identified as wild birds, fitting the pattern described in the blog post. That matters because much of the recent public attention around feline H5N1 has centered on raw pet food and raw milk, while outdoor exposure remains a persistent and likely underrecognized route. (wormsandgermsblog.com)

The Dutch story has developed in stages. Dutch authorities were first alerted on December 24, 2025, after two sick cats were reported on a dairy farm in Noardeast-Fryslân, Friesland; one cat tested positive for bird flu and died two days later. During the follow-up investigation, the Netherlands Food and Consumer Product Safety Authority, or NVWA, sampled cattle on the farm. On January 23, 2026, Wageningen University & Research announced that antibodies against H5N1 had been detected in one dairy cow, with no virus particles found in the animal or in milk samples tested at that point. (nvwa.nl)

Weese’s February 2 update added another notable detail: five cows on that farm had reportedly tested positive for H5N1 antibodies. That doesn’t prove active cow-to-cow transmission, and Dutch officials have emphasized that the current situation is not comparable to the U.S. dairy outbreak because no active virus has been detected so far in Dutch cattle or milk. Still, it does support the conclusion that cattle in Europe have been exposed, most likely through spillover from infected birds, though Weese notes other pathways can’t be fully excluded. A UK government risk note published in February 2026 likewise summarized the Dutch event as involving one initially identified cow and later four additional cows with antibodies. (wormsandgermsblog.com)

The broader feline context helps explain why these reports resonate. International Cat Care, responding to a recent review article on avian influenza in cats, highlighted concerns about exposure through dead birds, contaminated raw poultry, and unpasteurized milk. The underlying systematic review, published in Open Forum Infectious Diseases, identified 607 feline avian influenza infections in the English-language literature from 2004 to 2024 and estimated a 71.3% fatality rate among RT-PCR-confirmed feline infections. It also found a sharp increase in reports beginning in 2023, with H5N1, especially clade 2.3.4.4b, dominating recent cases. (academic.oup.com)

That evidence lines up with what front-line veterinarians have been seeing. In North America, multiple cat cases have already been linked to contaminated raw diets and raw milk, while outdoor hunting and farm exposure remain recurring risks. Washington state guidance for veterinarians has specifically urged clinicians to consider H5N1 in cats with compatible illness and exposure histories, including raw pet food ingestion or wild bird contact. The practical takeaway is that exposure history still does much of the diagnostic heavy lifting. (content.govdelivery.com)

Why it matters: For veterinary professionals, these updates reinforce the need to treat cats as both high-risk patients and useful sentinels. A single dead or neurologic cat may be the first sign of local wildlife exposure, contaminated feed, or broader farm-level transmission dynamics. The Dutch cattle finding is especially relevant because it expands the geographic footprint of dairy-cattle exposure into Europe, even if the epidemiology there currently looks very different from the U.S. outbreak. That means small-animal, mixed-animal, and public health veterinarians all have a stake in tighter triage questions, better PPE decisions, and faster reporting when cats present with acute respiratory or neurologic disease plus credible exposure risk. (wur.nl)

What to watch: The next key signals will be whether Dutch surveillance finds evidence of additional cattle exposure or active virus, whether more feline cases tied to wildlife rather than food are publicly reported, and whether veterinary guidance evolves to push even harder on avoiding raw poultry, raw milk, and unsupervised outdoor access for cats during local H5N1 activity. (wur.nl)