Avian flu is decimating poultry farms, driving up egg prices, and spreading beyond birds to unexpected species. Since 2022, more than 148 million farm birds — including chickens and turkeys — have been euthanized to contain outbreaks, sending ripple effects through the food supply.
The virus isn’t just a problem for farmers—consumers are paying the price too, with egg costs soaring to $7-$12 per dozen — an increase of 4.2% to 9.6%, according to the USDA.
Beyond egg prices, the avian flu is putting the lives of many animals at risk, including zoo populations and backyard flocks. As the virus continues to spread, experts are examining its risk to humans and the foods we consume.
How Avian Flu Crossed Borders and Species
While the avian flu, also called the H5N1 virus (bird flu), has existed for decades, it was confined to bird populations, such as aquatic birds, wild birds, or chickens, and mostly isolated in Asia, said Dr. Michael Angarone, a specialist in infectious disease at Northwestern Memorial Hospital in Chicago. The most severe form of the virus is Highly Pathogenic Avian Influenza (HPAI), which spreads rapidly and causes high mortality in infected birds.
However, in recent years, this virus found its way to the United States, originally affecting cows and dairy farm workers before affecting chicken farms and wild birds.
“What is somewhat unique,” Dr. Angarone says, is that we found it (in the U.S.) first in a mammal and then in a human, and then in birds.”
All 50 states have seen transmissions of the virus spread by wild birds’ feces and saliva. According to the CDC, the immediate risk to the general population is low, and there has been no person-to-person spread in the United States. Most cases have been in California, Colorado, and Washington, primarily in rural areas. With 68 confirmed human cases in the U.S. and one death, Dr. Angarone says it’s still something worth paying attention to and tracking.
“Now that we know that cows and cattle can become infected, we have to start protecting those working with those animals,” says Dr. Angarone. “The push by the CDC is that those workers should be wearing protective gear themselves, especially if they are around any animals that might be affected.”
A recent report in the Washington Post revealed a new virulent strain, H5N9, at a duck farm in California. Scientists are concerned that continued spread, alongside seasonal flu, could produce a new, more transmissible virus.
“A new strain of avian influenza has been identified for the first time in the United States, raising concerns that the virus is transforming in a way that could eventually cause wider outbreaks among humans,” the report says.
A recent CDC report also suggests human cases may be going undiagnosed, and therefore undercounted.
From Farms to Zoos: Avian Flu’s Growing Reach
Bird flu has infiltrated zoos in the U.S. According to The Guardian, a cheetah, mountain lion, Indian goose, and kookaburra were among the animals that died at Wildlife World Zoo near Phoenix. A wild, red-shouldered hawk died at a San Francisco Zoo, and a rare, red-breasted goose died at Woodland Park Zoo in Seattle. Researchers report that birds flying in and out of enclosures, especially during migration season, have caused an increase in cases.
Recent reporting by the New York Times revealed that three ducks died at the Queens Zoo, and as many as 12 more birds died at the Bronx Zoo. New York Governor Kathy Hochul recently ordered all live bird markets to be closed to stop the spread of the virus.
At the Lincoln Park Zoo in Chicago, officials confirm the avian flu as causing the death of a Chilean flamingo and harbor seal in early January. The Chicago Tribune recently reported that more than 100 dead birds lay along lakefront beaches, with avian flu suspected to be the cause.
“This is sad news for wildlife and for the zoo team. Not only are we facing the first known cases of HPAI in animals in our care, but we’ve lost two amazing animals,” says Lester E. Fisher, Director of Veterinary Services Dr. Kathryn Gamble, DVM, Dipl. ACZM, Dip. ECZM. “While highly pathogenic avian influenza is a naturally occurring virus in free-ranging waterfowl, more mammal species have been reported to be susceptible to HPAI since 2022.”
To protect the zoo’s animals, zoo officials will keep some bird species behind the scenes, and the McCormick Bird House will remain closed until further notice. Zoo visitors are not at risk of contracting HPAI, officials said.
Because the zoo has so many different animals, it can serve as an early warning system for disease outbreaks.
“We really think we’re poised to be helpful to the public health community and to the veterinary health community because we really have a lot of insight into how these transmissions are happening and how we can stop them,” says Seth Magle, director of the Urban Wildlife Institute at Lincoln Park Zoo.
How to Protect Yourself and Your Pets from Avian Flu
Despite the alarming spread among animals, human cases remain rare, says Mangle. However, he says cats are very susceptible to the disease. If possible, he suggests keeping cats inside and being on the lookout for any birds they drag near your home.
Dogs are not immune to the virus, and Mangle suggests watching dogs for generalized symptoms such as lethargy or fever, especially dogs that enjoy chasing birds. He also suggests taking down bird feeders, which encourage transmission.
Farmers, especially those who work with birds, are slightly more likely to contract avian flu. Dr. Angarone suggests staying vigilant to keep yourself and your animals safe.
“If you are on a farm or are around these farm animals, cattle or chickens, then protect yourself,” Dr. Angarone says. “And if any of those animals are sick, get them evaluated for bird flu. And if they are sick with bird flu, do the best you can to protect yourself when you’re around that animal.”
He also recommends the public avoid touching any dead bird, not just an aquatic one. “If you see a lot of dead birds, leave them there and call the Animal Control in your area,” he says.
Is Your Food Safe? What to Know About Avian Flu and What You Eat
There is no evidence that the virus is affecting beef or chicken meat, but it is important to cook food to a safe temperature to kill any harmful bacteria. Also, avoid raw eggs, and do not drink or consume raw milk or milk products.
“It’s important to know your milk is pasteurized so that anything that is in there is killed or inactivated. And if that means staying away from foods that are prepared with a raw egg or undercooked egg, I would until we have more information,” says Dr. Angarone.
Backyard Flocks at Risk: Steps to Protect Your Birds
Backyard flocks became more prevalent during the pandemic and persist due to the high price of eggs. According to the American Medical Association, owners of backyard flocks are encouraged to stay informed about where HPAI is occurring. They suggest the following to stop viruses from spreading:
- Bring pet birds indoors or ensure areas with backyard birds are fully enclosed, away from wild birds and their droppings.
- Wash or sanitize your hands before and after handling birds and when moving birds between coops.
- Secure all feed, drinking water, equipment, and other supplies away from wild birds and rodents.
- Prevent visitors from contacting your flock, and avoid visits to places with other birds.
- Know the signs of HPAI, and immediately report any suspected infections to your veterinarian or state animal health official.
- Call your veterinarian before bringing your bird(s) in to be seen.
How to Help
Support Lincoln Park Zoo’s Commitment to Conservation and Science
As one of the nation’s leading zoo-based science and conservation institutions, Lincoln Park Zoo is shaping the future of wildlife care and protection — both in Chicago and around the world. Through groundbreaking initiatives like the Urban Wildlife Institute, researchers are using Chicago as a model to better understand how cities and nature can coexist, helping to inform urban conservation efforts everywhere.
By supporting Lincoln Park Zoo, you help keep this vital institution free and open to the public, ensuring that families, students, and wildlife enthusiasts can continue to experience and learn from its world-class programs. Your support also fuels critical research, from wildlife conservation in Africa to urban ecology studies right here in Chicago, improving the lives of animals in zoos and in the wild.
Help an Animal Find a Home
If you’re reading this to learn how to keep your beloved pet safe, let it also inspire you to help an animal still searching for a home. PAWS Chicago has become a national model for the No Kill movement, providing rescue, adoption, and medical care to thousands of homeless cats and dogs each year.
By adopting, fostering, donating, or volunteering, you can be part of a compassionate movement to ensure every pet gets the love and care they deserve.
Susan Berger is a freelance journalist in Chicago and has written for the Washington Post, New York Times, and Chicago Tribune. She was a 2021 CDC Fellow through the Association of Health Journalists and a National Press Foundation Fellow in 2019 to study vaccines and dementia. She has also written for Health Magazine, National Post, Agence France-Presse, CBC, and Better Magazine. Ms. Berger has appeared on the Today Show, NBC Nightly News, BBC World News, CNN, WGN-TV, WTTW-TV, and CBC Radio. Her work can be viewed at www.bergerreport.com, and you can follow her on X @Msjournalist
