Bird Flu: What You Need to Know About H5N1 Avian Influenza

With outbreaks growing in scale and frequency, it’s more important than ever to understand how bird flu spreads, its symptoms, and what we can do to protect ourselves and the animals we care about. Read on to explore the key facts about H5N1 avian flu, its impact on humans and animals, and the systemic changes needed to prevent future pandemics.

What Is Bird Flu (Avian Flu) and Is Bird Flu Contagious?

Bird flu, or avian influenza, is a virus caused by influenza Type A virus. Currently, highly pathogenic bird flu has been devastating factory farms and wild bird populations and even raising concerns about its potential to jump to humans. While there are many strains of bird flu, H5N1 is the current strain infecting animals worldwide. This strain of bird flu is highly contagious amongst bird populations.

What Is H5N1?

H5N1 is just one of many subtypes of the avian influenza virus. It primarily infects birds, but in rare cases, it can infect humans, with serious—sometimes fatal—consequences. The virus spreads rapidly through bird populations via direct contact, contaminated water, or even airborne particles. While outbreaks of bird flu are not new, the scale and frequency of these events are increasing.

Can Humans Get H5N1 Avian Influenza?

Unfortunately, the H5N1 bird flu has infected more than two dozen people, including a child in California. During 2024, the Center for Disease Control (CDC) reported 55 human cases of H5 bird flu, with a total of 63 cases of H5 detected. At this time, human infections are uncommon where there has not been prolonged exposure to infected animals. A patient in Louisiana who was over 65 and had underlying medical conditions died from H5N1 bird flu in January 2025 after contracting the illness due to “a combination of a non-commercial backyard flock and wild birds.”

According to the CDC, the disease is still “mainly an animal health issue” and is widespread in wild birds, with sporadic outbreaks in farmed birds and mammals, and an ongoing multi-state outbreak in cows exploited for dairy. As of the first week of January 2025, the H5N1 virus has been detected in nearly 11,000 wild birds, affecting more than 130 million farmed birds, and 917 dairy herds across sixteen states since 2022.

What Are Bird Flu Symptoms in People?

Symptoms of bird flu (avian influenza, or H5N1) include:

• Conjunctivitis (eye redness and irritation)
• A fever of 100 degrees Fahrenheit or higher
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue

Symptoms of bird flu (avian influenza) viruses can appear between two and seven days after exposure. Respiratory symptoms, such as difficulty breathing or shortness of breath in moderate illness, can begin approximately three days after exposure and infection with an avian influenza H5 virus. Individuals infected with bird flu are thought to be contagious the first few days of their illness—similar to seasonal flu viruses.

Should I Be Concerned About H5N1 Bird Flu?

As of January 2025, there is a low risk to public health, and no person-to-person spread reported. However, this situation is developing, with the World Health Organization (WHO) declaring H5N1 avian influenza a global zoonotic pandemic. The majority of documented cases in the United States have been from agricultural workers working with infected dairy herds or culling infected flocks on factory farms.

Public health experts warn that the more the virus spreads in birds, the higher the risk of it mutating into a form that could spark a global pandemic.

How Does Bird Flu Spread?

Bird flu is highly contagious and transmissible through saliva, mucous, or feces in birds. Other infected animals may transmit H5N1 avian influenza through respiratory secretions and other body fluids (such as cows’ milk). At this time, person-to-person transmission has not been confirmed, but humans can be infected through a person’s eyes, nose, mouth, or if the virus is inhaled.

How Can I Protect My Companion Animals from Bird Flu?

An indoor-only house cat in Oregon recently died from H5N1 avian flu after eating raw frozen pet food, the Oregon Department of Agriculture (ODA) confirmed. Similarly, two cats (from two different households) in Santa Barbara County have died from the H5N1 virus after consuming raw milk or raw pet food.

Here are a few tips to keep companion animals safe from H5N1:

Keep cats indoors

While we always advocate for cats to stay indoors, it’s especially important to keep them inside and away from wild birds during this bird flu outbreak. Outdoor cats can possibly be infected by stepping in wild bird feces or killing and eating an infected wild bird or even rats and mice.

Don’t Feed Raw

Raw milk and pet food may contain live viruses, which animals can consume and quickly get infected. Most canned food goes through a cooking process, killing the virus, but double-check with the company if you’re unsure. Don’t feed your cats milk or other dairy products—ever—as it isn’t good for their digestive systems and can lead to diarrhea and vomiting.

Bathe Your Dog

After a walk—especially if you live in an area frequented by wild birds such as geese—wipe down your dog’s paws and any other areas that might have been exposed to bird droppings. If your dog is a sniffer or poop eater (as some unfortunately are!), ensure that they do not stop to sniff or consume geese feces. This is especially important if you have other animals, such as cats or birds, in your household.

According to Kristen Coleman, who researches airborne infectious diseases at the University of Maryland, symptoms of H5N1 avian influenza in companion animals can range from respiratory symptoms to mimicking rabies. Other symptoms of cats, who seem to be most susceptible at this time, infected with bird flu include:

• Loss of appetite
• Lethargy
• Fever
• Reddened or inflamed eyes
• Discharge from eyes and/or nose
• Difficulty breathing
• Neurological symptoms such as tremors, seizures, blindness, or incoordination

At this time, there is no known cure or specific treatment for the bird flu in animals—though supportive care, such as IV fluids, oxygen therapy, and antibiotics to manage symptoms is available. If you suspect your companion animal has bird flu, please contact your veterinarian immediately.

What Should I Do If I See an Animal Potentially Infected with Bird Flu?

If you suspect an animal might be infected with bird flu or has died from it, check with your state health department, state veterinary diagnostic laboratory, or state wildlife agency for information about reporting animals. Avoid direct contact with potentially infected or dead animals, using gloves or plastic bags to move them (if instructed by your local authorities to do so).

The Centers for Disease Control (CDC) also recommends reporting sick animals or unusual animal deaths to the state or federal government by calling the United States Department of Agriculture’s (USDA) toll-free number: 1-866-536-7593.

Bird Flu: A Global Zoonotic Pandemic Fueled by Human Activity

Factory farming is not just the largest source of animal cruelty on the planet—it’s also an incubator for diseases like H5N1 avian influenza. Animals on factory farms are confined in overcrowded, unsanitary conditions—making them the perfect breeding ground for diseases like bird flu to thrive and adapt.

As per federal policy—and without any cure or treatment for the H5N1 virus in animals—flocks infected with bird flu are killed through methods such as water-based foam and ventilation shutdown which cause extreme anguish. Water-based foam, which is the “recommended method” of the US government and industry groups for farmed bird species, obstructs the animals’ airways—similar to drowning or suffocation—and can take more than ten minutes to kill an animal.

Not only can viruses and diseases spread rapidly through individual factory farms, transport of animals and even workers traveling from one farm to another can increase the likelihood of spread to other industrial farms. Wild animals, who may feed on dead farmed animals infected with the virus, come in contact with bodily fluids from infected farmed animals, or drink from water troughs infected animals share, can then become infected and spread viruses or other potentially deadly illnesses to local wild animal populations—making it harder to contain the spread even if culling procedures were followed.

Because of the rapid spread and inability to contain this virus, California officials have recently declared a state of emergency over the spread of bird flu, which has infected at least 650 dairy herds throughout the state, representing approximately 75 percent of all affected dairy herds in the US.

In addition to H5N1, other pathogens can mix and mutate in these environments, potentially creating new, deadlier strains. In short, factory farms don’t just put animals at risk—they endanger us all.

Avian Influenza’s Impact on Wild Animals

Wild animals around the globe have been suffering from this highly contagious and deadly virus. H5N1 avian influenza has been documented in multiple wild species such as black and brown bears, coyotes, raccoons, red foxes, Virginia opossums, North American river otters, American mink, and marine mammals such as dolphins and polar bears. In fact, the virus has jumped to Antarctica, threatening already vulnerable animal populations.

However, wild animals in captivity are also susceptible to suffering from bird flu. Similarly to factory farms, zoos—with their concentration of animals in confined spaces and caretakers moving from enclosure to enclosure—act as breeding grounds for pathogens like H5N1.

By the end of 2024, multiple captive wild animals have succumbed to H5N1 avian influenza, which should be a wake-up call to us all. Five animals at Arizona’s Wildlife World Zoo and Aquarium—including a cheetah, mountain lion, swamphen, kookaburra, and an Indian goose—have all died from the H5N1 virus, exposing more than 25 employees.

In Washington, 20 big cats—including five American servals, four cougars, four bobcats, two Canada lynx, a Bengal tiger, Amur/Bengal tiger, an African caracal, Geoffroy’s cat, and Eurasian lynx—died from bird flu at the Wild Felid Advocacy Center. 

Most recently, the H5N1 avian influenza virus killed approximately 200 snow geese in Pennsylvania, with infected—but still living—birds at the two sites where the flock perished.

The Time to Act Is Now

H5N1 and other zoonotic diseases are warning signs that our current food system is unsustainable—for animals, the environment, and human health. Factory farming isn’t just cruel; it’s a ticking time bomb for global health.

As consumers, we have the power to drive change. By choosing plant-based options and demanding action from policymakers, we can help create a food system that’s healthier for everyone—humans, animals, and the planet.

The next time you hear about an H5N1 outbreak, remember: it’s not just a bird flu problem. It’s a factory farming problem. And together, we can fix it. Join thousands of people across the United States urging their federal legislators to end factory farming now.