H5N1 puts new pressure on companion animal practice

H5N1 avian influenza is increasingly relevant in companion animal practice, especially for cats. What began as a wildlife and poultry disease story expanded in 2024 and 2025 as infected dairy cattle, contaminated raw milk, and multiple raw pet food incidents created new exposure routes for indoor pets. Public health and veterinary agencies now emphasize that companion animals, particularly cats, can become severely ill after ingesting contaminated products, and the FDA has moved to require some pet food manufacturers to explicitly account for H5N1 in their food safety plans. AVMA coverage adds important scale: USDA had documented nearly 70 domestic cat infections in 2024 alone, and roughly 200 U.S. cat cases since the virus appeared in the country at the end of 2021. (fda.gov)

That shift didn’t happen in a vacuum. Since the U.S. dairy-cattle outbreak began in March 2024, state and federal agencies have documented high viral loads in raw milk and linked several feline illnesses and deaths to raw milk or raw pet food exposure. In December 2024, Oregon officials tied a house cat’s fatal infection to raw frozen pet food, and additional recalls and investigations followed in 2025, including cases linked to Savage Pet and RAWR Raw Cat Food. AVMA reporting also described fatal feline cases in San Francisco and Los Angeles tied to a contaminated raw chicken diet carrying the B3.13 genotype, reinforcing that commercial raw diets can be a direct vehicle for infection. Those events helped move H5N1 from a theoretical companion-animal risk to a practical exam-room conversation for small animal clinicians. (apnews.com)

The epidemiology remains dynamic. AVMA’s Veterinary Vertex discussion noted a lull in domestic poultry and mammalian cases during summer and early fall, followed by renewed infections and deaths associated with avian migration patterns. For companion animals, that means the outdoor exposure risk has not gone away even as foodborne transmission gets more attention. Cats can still be infected through predation and scavenging, and experts specifically highlighted ongoing circulation in wild birds and mammals such as house mice, which can bring the virus into cats’ environment. (avma.org)

The clinical picture is also sharper now. CDC guidance for cats and captive wild animals notes that H5N1 can range from mild illness to severe neurologic disease and rapid death. Respiratory signs may be present, but neurologic abnormalities can be especially prominent. California public health guidance has advised veterinarians to consider H5 infection in cats with raw milk or wild bird exposure, particularly when they present with seizures, acute ataxia, nystagmus, or cortical blindness. Cornell’s Animal Health Diagnostic Center has likewise highlighted testing for cats with compatible neurologic disease and histories that include ingestion of raw milk, raw meat, or contact with sick or dead birds. (cdc.gov)

The food-safety angle is where the story has changed most for practice teams and pet parents. The FDA has warned that recent investigations indicate transmission to cats through food, most often unpasteurized milk or uncooked meats, and has said H5N1 can be deadly to cats and also to dogs. In response, the agency said cat and dog food manufacturers covered by the Preventive Controls for Animal Food rule and using uncooked or unpasteurized poultry- or cattle-derived ingredients must reanalyze their food safety plans to include H5N1 as a known or reasonably foreseeable hazard. That makes H5N1 not just a clinical concern, but a manufacturing and compliance issue across parts of the pet food sector. AVMA experts added a practical wrinkle for clinics and clients: the virus can persist for long periods in frozen or refrigerated raw diets, so contaminated products may remain hazardous well beyond the initial production window. In one California-linked raw chicken product, the sell-by date extended to September 2026. (fda.gov)

Expert commentary is converging around a few practical messages. AAHA’s coverage of feline H5N1 case management says testing decisions should weigh both clinical presentation and risk-factor history, including raw foods, raw dairy, poultry exposure, and wildlife contact. STAT has also reported that companion-animal surveillance remains limited in the U.S., with experts arguing that the true scope of infection in cats may be underestimated. AVMA’s discussion reinforces that point by showing how quickly the epidemiology can shift week to week. Taken together, that suggests many frontline veterinarians may be seeing the consequences of a surveillance gap as much as a disease problem. (aaha.org)

Why it matters: For veterinary professionals, H5N1 adds a new layer to triage, history-taking, infection control, and client counseling. Cats with acute neurologic or respiratory disease now warrant more specific diet and exposure questions, including whether the pet has consumed raw milk, freeze-dried or frozen raw food, hunted birds or rodents, or lived near poultry or dairy operations. Clinics also need protocols for PPE, isolation decisions, sample submission, and reporting pathways, because suspected H5N1 cases can involve both animal health and human health follow-up. And for pet parents, this is a clear communication moment: “raw” now carries a more immediate, concrete infectious disease risk than many clients may realize. (cdc.gov)

Dogs appear less affected than cats in the current outbreak, but they’re not outside the risk conversation. FDA and CDC materials note that dogs can be exposed and that contaminated raw products may also create household exposure risks for people handling the food or caring for a sick pet. That broadens the veterinary role from diagnosing illness to helping households reduce risk through safer feeding practices, hygiene, and prompt reporting of suspicious cases. (fda.gov)

What to watch: The next phase will likely center on better companion-animal surveillance, more refined testing recommendations, and continued pressure on raw pet food makers as recalls, state alerts, and FDA oversight evolve. If additional feline cases continue to trace back to commercial diets or dairy exposures, expect stronger clinical guidance and possibly broader industry changes around sourcing, processing, and labeling. Seasonal wildlife dynamics also matter here: AVMA experts noted that case activity has risen again with bird migration, so exposure risk may continue to fluctuate rather than decline steadily. That last point is an inference based on the FDA’s current hazard-analysis posture, the pattern of recalls seen through 2025, and the epidemiology described by veterinary sources. (fda.gov)