Avian Influenza

Avian influenza is a disease caused by influenza A viruses that usually spread between birds, rather than people, and is different from the seasonal influenza virus. Avian influenza mainly affects birds, such as chickens, turkeys, geese, ducks, and swans, but it can affect other animals, such as cattle, foxes, and sea lions. People rarely get avian influenza, but when they do, it’s most often through direct unprotected contact (not wearing recommended personal protective equipment) with infected birds or other infected animals; human-to-human transmission is rare.

How Does Avian Influenza Spread?

Exposure to infected sick or dead animals is the main risk factor for getting avian influenza. Exposure to surfaces contaminated with animal secretions/excretions like saliva, mucus, and animal feces (poop) is another risk. Eating undercooked or uncooked poultry or eggs from an infected bird, or consuming unpasteurized milk from an infected dairy cow, could also be an exposure risk for infection with avian influenza viruses.

Symptoms and Illness

Avian influenza is caused by different influenza viruses than the seasonal flu, but some of the symptoms may be similar. Symptoms may appear within 1 – 14 days after exposure to a sick or dead animal, and may range from very mild to severe, including:

Fever
Cough
Sore throat
Runny or stuffy nose
Muscle or body aches
Headaches
Fatigue or tiredness
Conjunctivitis (red eyes)
Shortness of breath or difficulty breathing

Avian Influenza in Birds

Avian influenza viruses are generally categorized based on the severity of disease they cause in birds, namely:

Low pathogenic avian influenza (LPAI)
Highly pathogenic avian influenza (HPAI)

While most avian influenza viruses are low pathogenic, causing little or no signs of illness in birds, some avian influenza viruses are highly pathogenic and can cause severe illness and death in birds. H5N1 Highly Pathogenic Avian Influenza (HPAI) has been has been detected in Canada, including Toronto. The Canadian Food Inspection Agency (CFIA) is responding to cases in farmed birds, backyard poultry and wild birds. See the CFIA’s HPAI monitoring dashboard . If you have backyard hens, practice enhanced infection prevention and biosecurity measures . If you see a sick or dead bird in Toronto, contact 311.

Bird flu is spread by direct contact between infected birds and healthy birds. It can spread when healthy birds come into contact with or interact with equipment (including water and feed) contaminated by the saliva, secretions or feces of infected birds.

Bird Flu Symptoms in Birds

Bird flu is present in wild bird populations across the world. Typically, wild birds (particularly waterfowl such as ducks, geese and swans) carry bird flu without symptoms, but they can still spread the virus to domestic birds. Once infected, birds such as chickens, ducks and turkeys may show one or many of these symptoms:

Loss or lack of appetite
Low energy/tiredness (lethargy) or depression
Lack of coordination including tremors
Decreased egg production for poultry or pet birds
Swelling around the head, neck and eyes
Coughing and/or sneezing
Other symptoms such as diarrhea, and potentially, sudden death

Prevention

For Toronto Residents

There is a vaccine for avian influenza available to eligible high-risk groups, see Avian Influenza Vaccine (Arepanrix™ H5N1 Vaccine)
Do not touch wild birds.
Avoid contact with domestic birds such as poultry that appear sick or have died.
Only keep birds as pets if obtained from a reputable source; do not keep or care for wild birds.
Avoid contact with surfaces that have feces from wild or domestic birds.
Wash your hands thoroughly with soap and water right away after unavoidable contact with birds or their droppings.
Poultry and poultry products such as eggs are safe to eat when food is handled and cooked safely.
If you own or care for backyard poultry, there are more steps you can take to protect yourself and your birds from bird flu.
If you see a sick or dead wild bird, contact 311. Do not touch sick or dead animals, their feces (poop) or environment (e.g., bedding) or bring sick or dead animals into your home.
Report the following sick or dead animals to Toronto Public Health:
- Domestic Animals (e.g. pets, poultry, and other livestock)
- Wild birds (e.g. birds, geese, ducks, swans)
- Wild mammals (e.g. foxes, raccoons, skunks)
- To report to Toronto Public Health during business hours (8:30 a.m. – 4:30 p.m.), call 416-338-7600
- To report outside of regular business hours or on holidays, call 311 or 416-392-2489 (if calling outside the City of Toronto boundaries)

Information for Pet Owners

Do not let your pet touch wild birds. Keep your pets away from sick or dead animals and their feces (poop) by keeping them on a leash when outside.
Some birds infected with bird flu may not show symptoms.
Keep dogs on leash and supervise them closely in designated off-leash areas.
Consider keeping cats indoors to prevent contact with wild birds.
Do not feed pets (e.g., dogs, cats, etc.) any raw meat from game birds or poultry.
Keep pet food and water bowls indoors so they are not accidentally contaminated by birds or other animals.
Consider removing backyard bird feeders/baths or move them far away from pets and clean them with 10% bleach at least once every two weeks and then wash your hands.
Talk to your veterinarian if you have any concerns about your pet’s health.

Avian Influenza Vaccine (Arepanrix™ H5N1 Vaccine)

In June 2025, Health Canada approved the Arepanrix™ H5N1 vaccine for individuals who face ongoing occupational exposure to the virus. The federal government has obtained a limited amount of this vaccine, which is being made available to provinces and territories to support local vaccine programs.

The Ontario Ministry of Health has initiated Ontario’s Human Vaccines Against Avian Influenza (HVAI) program, which will target a small group of individuals occupationally exposed to avian influenza in the current context (i.e., no sustained human-to-human transmission and not in a pandemic state). Toronto Public Health (TPH) is participating in the provincial HVAI program and has contacted settings in Toronto where eligible individuals work to help facilitate administration of the vaccine.

Eligibility Criteria

The ministry recommends the following individuals are eligible to receive Arepanrix™ H5N1 vaccine:

People with ongoing contact with birds that are likely to be infected with avian influenza A(H5N1):
- Wildlife workers, researchers, and rehabilitators handling sick or dead birds
- Veterinarians and vet techs exposed to dead or sick birds likely infected with avian influenza A(H5N1) (e.g., necropsy)
People who handle live avian influenza A(H5N1) virus in labs:
- Examples include lab workers who manipulate, handle or culture live avian influenza A(H5N1) virus in research, industrial, or clinical settings.
Other individuals who may interact with live and well birds or animals that could be infected with H5N1, such as hunters and trappers, are at much lower risk of exposure and are not eligible for the vaccine at this time. However, eligible populations may change over time based on changing context, risk and evidence.

The vaccine is a two-dose series, with doses given at least 21 days apart. Summer 2025 is the ideal time to start the series, ahead of increased risk during fall bird migration and to allow spacing from the seasonal flu vaccine.

People who receive the H5N1 vaccine are not protected against the yearly seasonal influenza viruses and should still get the seasonal flu shot this fall.

A six-week interval between Arepanrix™ H5N1 and other vaccines is recommended, unless urgent immunization is needed.

Pregnant or breastfeeding individuals may consider vaccination after discussing the risks and benefits with a health care provider.

Additional Resources

For additional support, talk to your health care provider or Toronto Public Health at 416-338-7600 or call 811 to connect with a registered nurse day or night for free, secure, and confidential health service. To learn more, visit the following: