H5N1 keeps companion animals on the veterinary radar

H5N1 is no longer just a poultry or dairy story for companion animal practice. Federal agencies and veterinary groups are increasingly warning that cats, and to a lesser extent dogs, can be exposed through infected birds, contaminated raw pet food, unpasteurized dairy products, and farm-associated environments, with cats appearing especially vulnerable to severe disease. CDC guidance for veterinarians now emphasizes that infected cats may show nonspecific early illness, respiratory signs, neurologic abnormalities, or die suddenly, making exposure history central to case recognition. AVMA reporting has underscored how dynamic the epidemiology remains, with experts describing changes that can occur almost week to week as avian and mammalian infections shift. (cdc.gov)

That concern grew sharply after the March 2024 detection of H5N1 in U.S. dairy cattle, which expanded the virus’ practical relevance for small animal clinicians. CDC documented infections in indoor domestic cats in Michigan households connected to dairy workers, and USDA has said testing is encouraged for sick or deceased cats and other companion animals on premises with livestock showing signs consistent with H5N1. APHIS has also reported that many cats have been affected on H5N1-positive farms, likely through ingestion of contaminated materials, including raw milk from recently affected cows. AVMA’s Veterinary Vertex podcast added broader case context, noting that since H5N1 appeared in the U.S. at the end of 2021, about 200 cat cases have been documented nationally, including nearly 70 in 2025 alone. (cdc.gov)

Food exposure has become an equally important thread. FDA said manufacturers covered by the Preventive Controls for Animal Food rule that use uncooked or unpasteurized poultry- or cattle-derived ingredients must reanalyze their food safety plans to account for H5N1 as a known or reasonably foreseeable hazard. The agency has also issued public notices after H5N1 contamination was detected in certain raw cat food lots, including a 2025 alert involving RAWR Raw Cat Food Chicken Eats, where whole genome sequencing suggested a common source of contamination between product lots and a deceased cat. AVMA, meanwhile, has amplified alerts tied to raw pet food after indoor cats in Oregon became ill from H5N1 in early February 2025. In Veterinary Vertex, experts also pointed to California cat deaths linked to a contaminated raw chicken diet and noted that the implicated product had a sell-by date extending to September 2026, a reminder that frozen or refrigerated raw diets may preserve infectious risk for long periods rather than allowing it to fade quickly. (fda.gov)

The clinical picture is becoming clearer, too. CDC guidance says possible signs in cats include decreased energy and appetite, ataxia, circling, tremors, seizures, blindness, tachypnea, dyspnea, sneezing, coughing, and death with no obvious prior illness. A CDC-published report from Cornell investigators described domestic cats infected after ingesting commercial raw milk and advised veterinarians to include H5N1 on the differential list when cats have acute neurologic signs plus exposure to wild birds or raw poultry or dairy products. That same report noted isolation of H5N1 virus from the urine of a surviving cat, a finding that may influence how clinics think about specimen handling and environmental contamination risk. AVMA’s recent discussion also emphasized that predation remains a live exposure route because wild birds and even mammals such as house mice continue to be involved in the outbreak ecology, leaving outdoor and hunting cats at ongoing risk. (cdc.gov)

Outside government, veterinary infectious disease commentary has pushed the profession in a similar direction. Worms & Germs, a widely followed veterinary infectious disease blog by University of Guelph’s Dr. Scott Weese, has repeatedly argued that raw diets remain an avoidable H5N1 risk for pets and that cat illness linked to contaminated raw products is likely underrecognized rather than resolved. That perspective lines up with CDC’s standing recommendation against feeding raw pet food and AVMA’s broader policy support for pasteurization and caution around raw or undercooked animal-source products. The broader One Health framing is also familiar in AVMA content beyond influenza coverage, which has highlighted how pathogens can move through animal contact and contaminated environments in ways that are easy to miss if risk assessments focus too narrowly on food alone. (wormsandgermsblog.com)

Why it matters: For veterinary teams, the main shift is operational. H5N1 belongs on the differential list for cats with acute neurologic or respiratory disease when there’s any plausible exposure to raw diets, raw milk, wild birds, backyard poultry, dairy farms, or infected livestock environments. It also means intake protocols should capture household occupational exposure, PPE decisions may need to happen earlier in the visit, and client counseling should be more explicit for pet parents who feed raw foods or live near affected agricultural operations. Because H5N1 sits at the intersection of companion animal medicine, food safety, and zoonotic risk, small animal practice is now part of the One Health surveillance chain, not just adjacent to it. The practical takeaway from the recent AVMA discussion is that this is not a static risk: case counts, exposure routes, and geographic hot spots can change quickly, and products kept frozen or refrigerated may continue to pose a hazard well after purchase. (cdc.gov)

What to watch: The next developments are likely to come from three places: additional FDA action on raw pet food safety, continued USDA surveillance updates as dairy-associated H5N1 evolves, and more case reporting that clarifies how often dogs and cats are infected outside farm settings. Seasonal shifts in avian migration may also influence companion animal risk, as AVMA sources noted that poultry and mammalian infections rose again after a lull. If those data continue to point toward foodborne exposure in pets, expect stronger industry controls and even more direct guidance for frontline clinicians. (fda.gov)