Avian flu jumps warning

Bird flu is no longer showing up only in birds. In the United States, federal officials say highly pathogenic avian influenza A(H5N1) has been detected in more than 200 mammals since 2022, and the list now includes dairy cows, cats, foxes, skunks, bears, and marine mammals. (cdc.gov) Influenza is a shape-shifting virus that copies itself sloppily, more like a photocopier that smudges pages than a machine that prints perfect duplicates. Every new infected animal gives it another chance to pick up changes that help it survive in a new host. (who.int) Avian influenza usually spreads best in birds because birds are its usual host, the same way a house key fits one lock better than the others on a key ring. When the virus starts infecting mammals more often, scientists watch for signs that it is learning to fit mammal biology better. (paho.org) That is why the dairy-cow outbreak in the United States changed the conversation in March 2024. The Centers for Disease Control and Prevention called it the first time these bird-flu viruses had been found in cows. (cdc.gov) Cows matter because they live in dense groups, move across state lines, and are handled by people every day in milking parlors and barns. A virus in a wild fox is one thing; a virus in a commercial herd creates thousands of repeated chances for animal-to-animal and animal-to-human contact. (fda.gov) Scientists are also watching cats closely because cats get very sick from this virus. The American Veterinary Medical Association says dozens of cats in the United States have been infected since the dairy-cattle outbreak began, including barn cats, feral cats, indoor cats, and zoo cats. (avma.org) Some of those cat infections were linked to raw milk and raw pet food, which gives the virus a direct route from infected animals into a household. A Centers for Disease Control and Prevention case report described three California cats exposed to contaminated raw milk in 2024, with two deaths and one surviving cat that tested positive. (cdc.gov) That is why the Food and Drug Administration told pet-food manufacturers using uncooked poultry, meat, eggs, or unpasteurized milk to treat H5N1 as a foreseeable hazard in their food-safety plans. The agency was not reacting to a theory; it was reacting to a documented route of infection. (fda.gov) The newest warning is not that human spread is happening widely right now. The World Health Organization, the Food and Agriculture Organization, and the World Organisation for Animal Health said in July 2025 that the overall public-health risk was still low, while risk for people with frequent animal exposure was low to moderate. (woah.org) The warning is that the map keeps getting busier. The Pan American Health Organization said in March 2026 that from January 1, 2025 to March 9, 2026, H5N1 detections in the Americas were reported in 37 mammal species across two countries, and it noted an increase in reported mammalian cases during 2025. (paho.org) Public-health advice is still very concrete: do not touch sick or dead wild birds, keep pets away from carcasses, avoid raw milk, and be careful with raw pet food made from poultry or cattle. The reason is simple: every avoided exposure is one less roll of the dice for a virus that has already proved it can jump species. (cdc.gov)