Avian influenza, also known as bird flu, is caused by a group of viruses that originally came from wild birds.
One important genetic group (called a clade) of these viruses causes a severe type of bird flu known as high‑pathogenicity avian influenza (HPAI). This group is the 2.3.4.4b clade of the goose/Guangdong (Gs/GD)–related HPAI viruses. The viruses in this Gs/GD clade are a major concern because they can infect farm birds (like chickens and turkeys), pet and zoo birds, and wild birds, and they also have the potential to infect people and other mammals.
The Gs/GD viruses could become a bigger health threat to both birds and people. Compared with other bird flu strains, they are spread over a wider area of the world, so the chance of coming into contact with wild birds infected by these viruses is higher.
If you buy a new bird, you should find out where it came from and have a veterinarian check it for infectious diseases. The United States has rules that limit bringing pet birds into the country from areas where bird flu is present.
How Does Bird Flu Spread?
Bird flu spreads through direct contact with mucus, saliva, or other discharge from the nose and mouth, as well as droppings from an infected wild, farm, or pet bird. Dogs and cats can become infected if they hunt wild birds or eat the bodies of infected wild birds.
In early 2024, a specific type of bird flu virus in the Gs/GD 2.3.4.4b clade was found to have infected dairy cattle in the United States. The virus spread from farm to farm mainly when infected cows were moved.
What Are the Symptoms of Bird Flu?
In birds, the symptoms and severity of bird flu depend on the virus strain and the type of bird. Some virus strains cause only mild illness, while others can cause very severe disease with death rates up to 100%. Some birds might show no signs of sickness and recover, while others might die suddenly without any obvious symptoms.
Birds that show signs of breathing problems or other signs of illness should be quickly separated from other birds and examined by a veterinarian. The vet can test for bird flu by sending samples to a lab where they use molecular tests to detect the virus.
Are There Bird Flu Vaccines?
Vaccines exist for some types of bird flu in farm birds. However, vaccinating poultry against HPAI requires special emergency approval from the US Department of Agriculture (USDA). In 2023 the USDA started vaccinating the endangered California condor, but vaccination of poultry and pet birds is not allowed.
A key way to prevent infection is to keep domestic birds away from wild birds that could carry the virus.
Can Cats and Dogs Get Bird Flu?
In 2022 and 2023, several deadly infections with the Gs/GD‑related HPAI strain of bird flu were reported in house cats (in the United States, South Korea, France, and Poland) and in one dog (in Canada). Most of these pets spent time outdoors and probably became infected by touching or eating dead wild birds that were infected. A few of these cats got infected after being given raw poultry meat or pet food containing raw poultry.
Because the bird flu virus is shed both in discharges from the nose and mouth and in droppings, it is possible for cats to infect other cats, but the spread of bird flu from cat to cat seems to be extremely rare.
Common symptoms of bird flu in cats include:
extreme tiredness or weakness
loss of appetite
fever
trouble breathing (shortness of breath)
nervous system problems (such as seizures or loss of coordination)
digestive problems (vomiting or diarrhea)
jaundice (yellowing of the skin or eyes)
death
In early 2024, some barn cats died on farms where dairy cows were infected. These cats became infected after drinking raw (unpasteurized) milk from the sick cows.
How Can I Protect My Pet From Bird Flu?
Any animal that is suspected of having bird flu should be kept away from other pets. Anyone handling a possibly infected animal should wear personal protective equipment (PPE), such as gloves and a mask. After contact, handlers should wash their hands well with soap and water.
When HPAI is known to be present in wild birds in a particular area, pet owners should keep their pets indoors if possible, or supervise them outside to decrease contact with wild birds.
Cooked poultry, pet foods made with cooked poultry, and pasteurized milk are safe for your pet to eat. The high temperatures used in cooking and pasteurization kill HPAI viruses.
For More Information
Also see professional content regarding avian influenza in poultry and wild birds.
