H5N1 signals widen with Washington cat death and Dutch cow case

A fatal H5N1 infection in an outdoor cat in Washington state and the first reported detection of H5N1 antibodies in a European dairy cow, in the Netherlands, are adding to concern about how broadly avian influenza is moving across species. Scott Weese highlighted both developments in recent Worms & Germs posts, pointing to a Washington cat that likely picked up infection through wildlife exposure and to Dutch testing that found evidence of prior H5N1 infection in one dairy cow after a farm cat on the same premises tested positive. Dutch investigators said no active virus was detected in the cow or the rest of the herd at the time of testing, and Wageningen researchers described the finding as Europe’s first known bovine H5N1 antibody detection. (wur.nl)

Why it matters: For veterinary professionals, these cases reinforce two practical points: cats remain a high-risk spillover species, and cattle surveillance outside the U.S. now matters, too. The Dutch case doesn’t show active cow-to-cow spread, but it does confirm that European dairy cattle can be exposed. At the same time, growing literature on feline H5N1 has shown a sharp increase in reported cat infections since 2023, with many cases linked to hunting, raw food, raw milk, or farm exposure. That means small-animal, mixed-animal, and dairy veterinarians all need sharper exposure histories, stronger PPE habits, and clearer client guidance for pet parents about outdoor access and raw diets. (wur.nl)

What to watch: Watch for more Dutch herd-level serology results, any added European cattle detections, and whether public health agencies update guidance for veterinarians handling exposed cats or farm-linked companion animals. (wur.nl)