H5N1 reaches companion animals, raising new questions for vets

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H5N1 is no longer just a poultry, wildlife, or dairy cattle concern for veterinarians. Companion animals, particularly cats, have emerged as a clinically important and sometimes overlooked part of the outbreak, with U.S. agencies, veterinary organizations, and industry publications all pointing to severe feline disease after exposure to infected birds, raw milk, contaminated raw pet food, or contaminated environments linked to livestock operations. AVMA’s Veterinary Vertex recently emphasized how quickly that risk picture has grown, noting that USDA had documented nearly 70 domestic cat infections in 2025 alone and roughly 200 U.S. cat cases since the virus appeared domestically in late 2021. (fda.gov)

That concern has built over the past two years as H5N1 expanded into dairy cattle and other mammals in the U.S. A CDC report published February 20, 2025, described two indoor domestic cats in Michigan households with dairy workers that developed respiratory and neurologic illness and died, despite no known direct exposure to infected farms. The report said veterinarians in states with confirmed H5N1 in livestock should obtain household occupational information when evaluating suspect cases, underscoring how exposure histories now extend beyond the animal itself. (cdc.gov)

Food exposure has also become a major part of the risk picture. The FDA has said cats and dogs can be infected when they consume uncooked or unpasteurized poultry- or cattle-derived products that have not undergone a virus-inactivating step such as cooking, canning, or pasteurization, and it specifically noted that cats can suffer severe illness or death. In response, the agency required covered cat and dog food manufacturers using such ingredients to reanalyze their food safety plans to include H5N1 as a known or reasonably foreseeable hazard. AVMA’s recent discussion of companion-animal cases added another practical point for clinicians and owners: the virus can persist for long periods in frozen or refrigerated raw diets, so contaminated products may remain hazardous in home freezers or refrigerators long after purchase. (fda.gov)

That regulatory shift followed real-world cases. The FDA linked certain lots of RAWR Raw Cat Food Chicken Eats to an H5N1-infected cat, and a separate 2025 recall involved Savage Cat Food chicken products after illnesses in cats in multiple states. Those episodes reinforced a broader pattern seen in public reporting and agency alerts: raw diets have become a recurring exposure pathway in feline H5N1 cases. The AVMA podcast also referenced fatal cat cases in San Francisco and Los Angeles tied to a contaminated raw chicken diet, illustrating how commercial raw products have remained part of the exposure picture even as specific viral genotypes shift over time. (fda.gov)

Industry and professional guidance has grown more specific as the outbreak has evolved. AAHA, summarizing CDC recommendations for practice teams, has highlighted PPE for staff handling suspected cases and the importance of asking about household jobs and possible farm-linked fomite exposure, such as contaminated clothing. That advice aligns with the CDC’s Michigan investigation, which raised concern that infected cats may create human exposure risk even if documented cat-to-human H5N1 transmission has not been confirmed in this outbreak. AVMA’s reporting also noted that case activity has risen again alongside avian migration patterns and ongoing infections in wild birds and mammals such as house mice, reinforcing that predation and wildlife contact remain important risks for cats, especially those that go outdoors. (aaha.org)

Why it matters: For veterinary professionals, H5N1 in companion animals is now a triage, infection-control, diagnostic, and client-education issue. Cats with acute respiratory signs, neurologic disease, sudden decline, or unexplained death may warrant questions about raw food, raw milk, hunting behavior, wild bird contact, and whether anyone in the household works with dairy cattle or poultry. It also means practices may need clearer PPE protocols, staff training, and reporting pathways with state animal health and public health officials. For pet parents, the prevention message is increasingly consistent: keep cats indoors when possible, prevent contact with sick or dead birds, and avoid feeding raw milk or raw diets made with uncooked poultry or cattle ingredients. The added counseling point from recent AVMA coverage is that refrigeration or freezing does not make contaminated raw diets safe. (cdc.gov)

There’s also a wider One Health implication. Each mammalian spillover event adds pressure for better surveillance, and some experts have argued that companion animals remain a blind spot in federal oversight and routine monitoring. That doesn’t mean household pets are driving the outbreak, but it does mean veterinarians are often the first line for recognizing unusual cases that sit at the intersection of animal health, food safety, and public health. (statnews.com)

What to watch: The next phase is likely to center on expanded surveillance in cats, more detailed state reporting guidance, and continued FDA attention on raw pet food manufacturing and recalls as regulators and clinicians try to close gaps in how companion animal exposures are detected and prevented. Seasonal changes in wild-bird activity and continued popularity of raw diets may keep both wildlife-linked and food-linked feline exposures in focus. (fda.gov)