Avian influenza, also called avian flu or bird flu, is a disease that is spread primarily among water birds and is caused by flu viruses. Water birds (such as ducks, geese, gulls, and swans) can carry bird flu, sometimes without looking sick. Infected birds spread the virus through their saliva, nasal fluid, and feces to each other, and sometimes to poultry and animals.
There are many types of bird flu viruses. Some cause no or only mild signs or symptoms of disease in poultry, and others, called highly pathogenic avian influenza (HPAI), can cause severe disease and death in poultry and other birds. The H5N1 virus is a type of HPAI that has been circulating in the US since 2022 and has spread to mammals, including dairy cows and cats.
Some bird flu viruses can infect humans, but the risk is low. How sick a person becomes depends on the type of bird flu. Symptoms can range from no or mild illness to severe disease and death. Most people with H5N1 in the US have had conjunctivitis (red or inflamed eyes) and fever. Some have had mild respiratory illness. However, a small number of severe cases of illness and death have been reported.
Protect yourself and others by following these guidelines:
H5N1 in Wild Birds
Report groups of sick or dead birds immediately.
Some people may have to handle a dead bird because it is on their property. Follow these steps if you need to do so:
H5N1 in Poultry and Backyard Flocks
Report groups of sick or dead birds immediately. For poultry, call the NYS Department of Agriculture and Markets at 518-457-3502. They oversees surveillance for bird flu in poultry, including the live bird markets in NYC and coordinates testing and response efforts. Find more information about bird flu surveillance in poultry on the NYS Agriculture and Markets webpage.
If you own or care for chickens or other poultry, follow these tips:
Signs of illness in poultry include:
Learn more about how to protect your chickens or other poultry from bird flu by visiting the USDA and Cornell Cooperative Extension.
H5N1 in Cats and Other Mammals
Mammals can become infected if they eat infected birds, eating or drinking raw food or raw dairy products, or spend time in an area contaminated with bird flu viruses. The H5N1 virus has been found in several types of mammals, including dairy cattle, stray and domestic cats, foxes, raccoons, skunks, farmed mink, sea mammals, and zoo animals such as tigers and leopards.
Cats can get very sick and sometime die from bird flu. Cats have become infected from drinking raw (unpasteurized) milk, eating raw pet food or uncooked poultry, or eating infected birds. Signs of illness in cats may include seizures, trouble walking, fever, difficulty breathing, loss of appetite, vomiting, diarrhea and behavior changes.
Follow these tips for protecting cats:
Getting sick with bird flu from cats is unlikely, but pet owners should always make sure to avoid close contact with sick cats.
H5N1 bird flu has not been detected in outdoor cats in NYC, however, it may be possible for cats to catch the virus from infected birds, particularly water birds, they hunt.
If you interact with stray or feral cats, or work with a cat colony, take precautions to reduce the risk to you and any pet cat you may have at home for H5N1 and other diseases spread among cats. Avoid touching cat feces and urine (or items that may be contaminated with feces or urine), and remove any contaminated shoes or clothing before entering your home.
For more information, visit AVMA: Avian Influenza in Cats.