H5N1 puts companion animals, especially cats, on vets’ radar

Companion animals are no longer a side note in the H5N1 outbreak. As highly pathogenic avian influenza has spread through wild birds, poultry, and U.S. dairy cattle, veterinary attention has increasingly turned to cats, and to a lesser extent dogs, because of documented spillover tied to raw food, raw milk, infected wildlife, and farm-associated exposure. FDA, CDC, USDA, and veterinary organizations have all updated guidance or public messaging as these cases have accumulated. (fda.gov)

What changed over the past year is that H5N1 risk for pets became more concrete, and more practical, for small animal clinicians. CDC documented H5N1 infection in indoor domestic cats in Michigan households connected to dairy work in May 2024, and advised veterinarians to use PPE and gather occupational histories when evaluating cats with compatible illness in affected areas. Around the same time, reports tied feline illness and death to ingestion exposures, including contaminated raw milk and raw pet food, shifting the conversation from theoretical susceptibility to real-world household risk. (cdc.gov)

Regulators responded accordingly. FDA said cat and dog food manufacturers covered by the Preventive Controls for Animal Food rule and using uncooked or unpasteurized poultry or cattle ingredients must reanalyze their food safety plans to include H5N1 as a known or reasonably foreseeable hazard. The agency has also issued consumer-facing alerts after testing found H5N1 contamination in certain raw cat food lots, including a notice stating genomic evidence suggested a deceased cat and contaminated food shared a common source. USDA, meanwhile, said in January 2025 that it had identified a genetic link between potentially infected turkeys, virus detected in raw pet food, and an infected household cat, prompting tighter turkey surveillance before slaughter in affected states. (fda.gov)

The clinical picture in cats is part of why this matters so much. Cats appear especially vulnerable to severe illness and death, and published reports have described neurologic as well as respiratory disease. A 2025 CDC Emerging Infectious Diseases report described isolation of H5N1 virus from cat urine after raw milk ingestion, adding to concern that infected cats may shed virus through routes that complicate household and clinic infection control. Cornell’s veterinary experts have also highlighted recent feline cases linked to contaminated commercial raw diets, unpasteurized milk, and contact with wild birds or cattle. (wwwnc.cdc.gov)

Industry and expert commentary has largely converged on the same message: exposure history now matters as much as presenting signs. AAHA has urged practices to prepare staff, reinforce infection-control protocols, and ask about household occupational exposure when H5N1 is on the table. Cornell shelter medicine experts have advised asking specifically about raw diets and raw milk, and have recommended isolation for suspect feline cases because, while ingestion appears to be the main route in cats so far, influenza viruses can evolve in ways that change transmission dynamics. (aaha.org)

Why it matters: For veterinary teams, this is a disease-surveillance issue, a workplace-safety issue, and a client-communication issue all at once. In practice, that means considering H5N1 in cats with acute neurologic or respiratory disease, especially if they’re fed raw diets, drink unpasteurized milk, hunt birds, live on or near farms, or share a household with dairy or poultry workers. It also means reviewing PPE use, isolation workflows, specimen handling, and referral pathways with state animal health and public health partners. The broader implication is that companion animal medicine is now part of the One Health response to H5N1, not just a downstream observer of it. (cdc.gov)

For pet parents, the prevention message is straightforward, and veterinarians are likely to be the ones delivering it: avoid raw milk, avoid raw or underprocessed animal-source diets, prevent hunting and scavenging, and limit contact with sick or dead birds and other wildlife. For clinics, the harder question is how much hidden companion-animal infection may already be occurring. Surveillance remains limited, and Cornell’s Feline Health Center launched work in 2025 specifically to better understand how often cats are infected, whether they can transmit onward, and what role they may play in the broader ecology of H5N1. (vet.cornell.edu)

What to watch: The next phase will likely include more targeted testing guidance for small animal practice, additional food-safety actions involving raw pet products, and clearer recommendations for managing exposed pets as researchers and agencies refine the risk picture for cats, dogs, clinic staff, and pet parents. (fda.gov)