H5N1 updates put cats and cattle back in focus

CURRENT FULL VERSION: A dead outdoor cat in Washington state and a cluster of antibody-positive dairy cows in the Netherlands are the latest reminders that H5N1’s animal health footprint keeps widening, even when the individual events aren’t entirely surprising. The Washington case appears to be a wildlife-linked spillover into a domestic cat. The Dutch finding is more notable strategically: it’s the first reported evidence of H5N1 exposure in European cattle, and it emerged only after a cat on the same farm tested positive. (cms.agr.wa.gov)

The Dutch investigation began after H5N1 was confirmed in a domestic cat from a dairy farm in Friesland. Wageningen University & Research said milk samples from 20 cows and a bulk tank sample were collected as part of follow-up monitoring. PCR testing found no active virus, but one cow initially tested positive for H5N1 antibodies, indicating prior exposure. That cow had reportedly shown mastitis and reduced milk yield in mid-December 2025, then recovered. Subsequent reporting from Worms & Germs said five cows on the farm were eventually found to have antibodies, strengthening the case that spillover into cattle had occurred. (wur.nl)

That distinction between antibodies and active infection matters. Dutch authorities emphasized that no virus particles were found in the cow, that none of the other tested animals were carrying active virus when sampled, and that the farm’s milk was being directed only into pasteurized products while the investigation continued. ECDC likewise said its risk assessment did not change: risk remained low for the general public and low to moderate for people with occupational or direct exposure to infected animals or contaminated environments. (wur.nl)

The Washington cat case is less complex, but still important for clinicians. In a February 17, 2026 state update, the Washington State Department of Agriculture listed one confirmed domestic cat detection in Grant County, dated January 20, 2026, with wild birds as the suspected source. That fits the state’s earlier veterinary guidance, which noted that cats are most likely to be infected on affected poultry or dairy farms, by eating infected wild birds, or through contaminated raw products including raw milk and raw pet food. The agency said there was no evidence of cat-to-cat or cat-to-human transmission in the cases reviewed at that time. (cms.agr.wa.gov)

Industry and expert commentary has been cautious rather than alarmist. Scott Weese, writing in Worms & Germs, framed the Dutch cattle findings as another likely bird-to-cattle spillover and argued that the cat death and cattle serology both reinforce familiar prevention steps: limit outdoor exposure for cats when avian influenza is active locally, and avoid raw poultry-based diets. International Cat Care, responding to a recent review article on avian influenza in cats, highlighted the sharp rise in feline cases since 2023 and noted that H5N1 infections in cats have been reported globally, most often with respiratory signs, neurologic signs, and sometimes blindness; the review also found high mortality among reported feline cases, while acknowledging that some infections may be subclinical. The same summary emphasized that most reported feline infections were linked to bird-to-cat transmission, especially ingestion of dead birds or contaminated raw chicken, but also described cases tied to raw milk from infected cattle and discussed documented concern about feline-to-human transmission in settings such as tiger outbreaks in Thailand and a cat shelter outbreak in New York. International Cat Care’s practical advice was straightforward: avoid feeding raw poultry or unpasteurized milk, prevent farm cats from drinking on-farm milk, reduce access to dead birds where possible, and seek prompt veterinary care for cats with respiratory or neurologic signs. Federal agencies in the U.S. have been making similar points. FDA says H5N1 can be deadly to cats and urges pet parents to carefully weigh the risks before feeding uncooked meat or uncooked pet food, while CDC says it does not recommend feeding raw pet food or treats to dogs and cats. (wormsandgermsblog.com)

Why it matters: For veterinary teams, these updates sharpen two surveillance lessons. First, cats may be the first visible signal that H5N1 is circulating around a farm or household environment, especially because feline disease can be severe and obvious. Second, cattle infections may be missed in real time if animals are no longer shedding by the time testing begins, which makes serology and retrospective history, such as mastitis or milk drop, more important. That has implications for differential diagnosis, farm biosecurity conversations, and client counseling for both companion-animal and mixed-animal practices. The feline review summarized by International Cat Care adds another practical point for clinicians: not every infected cat will present the same way, and some may be asymptomatic, but when illness does occur it often includes respiratory or neurologic signs and can be rapidly fatal. (wur.nl)

The updates also reinforce a client communication challenge veterinarians are already managing: pet parents may still underestimate foodborne exposure. FDA, CDC, and AVMA all continue to advise against raw or unpasteurized animal products because of infectious disease risk, and H5N1 has now repeatedly made that advice more concrete for cats. For practices, that means prevention messaging should stay specific: keep cats from scavenging birds, avoid raw milk, avoid raw pet food, and use extra caution around farms or regions with active avian influenza activity. International Cat Care also pointed to practical hunting-reduction steps that may help lower exposure risk outdoors, including more daily play, diets that reduce hunting drive, and bird-warning collars, though those measures are adjuncts rather than substitutes for core biosecurity and feeding advice. (fda.gov)

What to watch: The next key signals will be whether Dutch follow-up testing finds broader evidence of exposure beyond this one farm, whether any active virus is detected in European cattle, and whether more U.S. states report wildlife-linked domestic cat infections rather than only farm- or food-associated cases. It will also be worth watching whether veterinary and public-facing guidance increasingly emphasizes cat-specific exposure reduction, given the growing global case count in felines and the severity described in recent reviews. For now, the Washington and Dutch reports don’t rewrite H5N1 risk, but they do add another layer to how veterinarians should think about spillover, surveillance, and prevention across species. (wur.nl)