Bird Flu

Highly pathogenic avian influenza (HPAI) is an extremely infectious and sometimes deadly disease known as “bird flu” that spreads rapidly among domestic and wild birds.

Bird flu has been an emerging concern for over a decade. The 2014–2015 HPAI outbreak killed at least 50 million birds and caused an estimated $1-3 billion in damage to the economy. Since 2022 the current HPAI outbreak (H5N1) has resulted in the loss of tens of millions of birds at poultry operations and has cost over $1.7 billion.

Despite the “bird flu” moniker, HPAI mutates and spreads to other species, including our own. It’s currently ripping across industrial scale dairies in the United States, from coast to coast. The Centers for Disease Control has confirmed HPAI in nearly half the dairy herds in California — the largest dairy producer in the nation — while outbreaks of the virus in poultry have been confirmed in all 50 states. This outbreak of HPAI is significant because of the spread of the disease across mammals and into dairy cows in a way that has never been seen before.

Most people falling ill have been working with cattle at industrial dairy operations, although there have also been several confirmed cases in children in California’s Bay Area, potentially linked with consuming raw milk. Meanwhile, cats (domestic and feral) and rodents have also been infected on dairy farms, whether from drinking contaminated milk or from proximity to infected cattle.

The USDA has also identified a positive case of HPAI in an Oregon “backyard” pig. Cases like these, where HPAI spills over to new species, particularly in pigs, along with the increasing cases in humans, make mutations more likely. And those mutations increase the risk the virus could change to allow human-to-human transmission. The CDC has stated that currently the risk is low for the human population and most cases in the United States have been “mild.”

But many experts worry that without more precautions, HPAI could be the next pandemic. And it has already taken a severe toll on domestic animals, food supply chains, and wildlife. mission to make a difference!

More than 180 species of wild birds and mammals have contracted HPAI, including federally protected wildlife like endangered California condors, a polar bear, and many animals in zoos and wildlife refuges, from black bears to mountain lions. This virus also has been decimating marine mammals. When pathogens like bird flu are allowed to spread unchecked in both the wild and among captive animals, it can cause ecological havoc that increases risks to wildlife. 

A new study provides the clearest picture yet of how biodiversity loss and climate change fuel the rise of diseases like HPAI; a warmer world with degraded ecosystems is ripe for the proliferation of deadly pathogens. 

The California Condor Recovery Program successfully vaccinated California condors to protect them against HPAI, but of course this is not a feasible solution to protect all wildlife at risk. Instead, we need to turn to the roots of the problem: habitat loss, exploitation, and animal agriculture. 

Agriculture is the leading cause of deforestation and habitat loss. As a result of this ever-weakening barrier between human and wild communities, we have seen an uptick in viruses that jump from animals to people. Infectious diseases originating from animals (“zoonotic disease”) have emerged following deforestation and wildlife exploitation.  

The stress and filth of intensive, crowded confinement of animals and their waste also exacerbates the evolution, mutation, and spread of pathogens. This is why 80% of U.S. antibiotics are used not to help people fight infections, but to prevent disease in farmed animals who aren’t sick yet. This increases the risk of “superbugs” or antibiotic-resistance bacteria that can make even mild infections in people much more dangerous.

Experts have long warned that factory farms are pathogen incubators, putting the most marginalized communities at the greatest risk. Community health and safety, like factory farms themselves, are an issue of environmental justice. The people who are exposed to bird flu, or other pathogens, during their work at dairy and poultry facilities, for example, and the communities nearest factory farm locations, are often the first impacted. These same communities are statistically the most marginalized and vulnerable of U.S. communities with the least access to affordable health care or workplace safety measures like personal protective equipment or sick days.

Bird flu has resulted in the deaths of millions of farmed and wild animals but isn’t yet widespread in humans. We’ve seen how quickly novel pathogens can spread following the COVID-19 pandemic. To prevent avian flu from becoming the next pandemic, agencies should be testing animals and workers — not just in dairies but across industrial animal facilities. If the virus takes off in hogs, we may be unprepared for the ensuing crisis. Pigs tend to be better hosts for enabling pathogens to mutate such that they can infect people.

Federal agencies like the CDC should take urgent action, including improving epidemiological knowledge about this outbreak by increasing the number of dairy workers tested for bird flu, proactively testing people associated with meat production beyond dairies, testing for the virus in farmed animals, milk, and farm waste and wastewater, and releasing this information to the public, including more detailed geographic data among livestock operations while protecting the privacy rights of workers.

Public transparency must also include agency data about where disease is spreading in confinement operations and how carcasses and contaminated waste is disposed to prevent further spread of disease from infected facilities. The USDA should act to prevent the most problematic forms of carcass- and infected-waste disposal to keep the virus from causing additional spread to exposed wildlife, public health, and environmental resources.

Instead, the Trump administration has made it far more challenging to address this outbreak by putting a freeze on the CDC’s ability to monitor HPAI and limiting data and knowledge sharing by withdrawing from the World Health Organization.

But there are real steps we can all take to redouble efforts to protect biodiversity and stop the next pandemic. That means shifting away from high-risk industries like factory farming.

One of the key risks comes from drinking raw milk as well as handling sick cattle, poultry and wild birds, and backyard chickens and hogs. Beyond worker safety and extra sanitation measures in farming, changing what we eat can help protect ourselves and the planet. Shifting away from animal-based foods — particularly dairy and poultry — toward plant-based meals and beverages can help alleviate the pressure on wildlife and public health posed by these industries.

The Center is closely monitoring the outbreak of HPAI and its impact on wildlife. We’ve worked with partners to urge the federal government to implement effective, humane, and ecologically sound protocols for implementing biosecurity measures and responding to outbreaks. And we’re working to educate the public on HPAI and its connection to industrial animal agriculture and biodiversity loss.

For over a decade, the Center has cautioned people that to protect wildlife and the wild places we love, we must look at how we farm and what we eat. We work through legal, policy and campaign channels to take on the threat to wildlife and human communities from zoonotic disease and the risk factors that elevate this situation to crisis level, such as wildlife trade, habitat loss and the intensive, closely confined factory farms that make up most of U.S. animal agriculture.

Read more about the Center’s positions: 

• Food X: Bird Flu Highlights the Problems with Factory Farming 
• Opinion: Bird Flu is Here: We Need Health Officials Pushing Vaccines, Not Raw Milk 
• Letter: CDC Urged to Accelerate Response to Escalating Bird Flu Outbreak in Industrial Dairy Cattle 
• Watch: Webinar on the Concentrated Risk of HPAI in Animal Agriculture 
• Read: The Center’s work during the COVID-19 pandemic and learn how on-site emergency culling creates severe environmental issues 

Federal Comments:

• The USDA’s Swine Health Improvement Plan (SHIP) 
• Programmatic Environmental Impact Statement (PEIS) for Outbreak Response Activities for Highly Pathogenic Avian Influenza Outbreaks in Poultry 
• Emergency Response for HPAI Outbreaks in the U.S. Migratory Bird Flyways Supplemental Environmental Assessment