Avian influenza (AI), commonly known as “bird flu,” is a type “A” influenza virus that can infect domesticated and wild birds, including:

  • chickens
  • turkeys
  • pheasants
  • quail
  • ducks
  • geese
  • guinea fowl
  • pigeons

There are different strains of the influenza A virus that naturally occur in wild aquatic birds. Sometimes it does not make the bird sick. However, the influenza A virus is highly contagious, and wild birds can transmit the virus through contaminated saliva, nasal secretions and feces.

Ontario poultry is safe to eat. Avian influenza is not a threat to food safety. You should always use proper cooking times, temperatures and handling techniques with poultry, meat and eggs.

Clinical signs

There are two categories of avian influenza A virus:

  • low pathogenic avian influenza A (LPAI)
  • highly pathogenic avian influenza A (HPAI)

In infected birds, LPAI  viruses cause no or mild disease and HPAI viruses can cause severe disease or death. In the right conditions, a LPAI virus can mutate into a HPAI virus.

Some, or all, of the following clinical signs are evident in infected birds:

  • a drop in production of eggs, many of which are soft-shelled or shell-less
  • coughing and sneezing
  • diarrhea
  • hemorrhages on the hock
  • high and sudden mortality rate
  • quietness and extreme depression
  • swelling of the skin under the eyes
  • wattles and combs become swollen, discoloured and congested

The incubation period of avian influenza ranges from 2–14 days.

If you suspect avian influenza at your farm, contact your veterinarian immediately.

Virus transmission

The influenza A virus is transmitted by:

  • direct contact between infected and susceptible birds
  • indirect contact through viral droplets in the air
  • exposure to contaminated surfaces, objects and equipment

Droplets from the respiratory tract often contain a high level of HPAI virus, but the large amount of contaminated feces from AI viruses make fecal contaminated surfaces and objects a significant mode of transmission. People can transmit AI viruses to other premises through contaminated clothing, shoes and shared equipment and vehicles.


Introduction of influenza virus into commercial poultry operations occurs most commonly through these sources:

  • other domestic and confined poultry
  • contaminated equipment
  • migratory waterfowl and other wild birds
  • domestic or wild pigs
  • companion or pet birds
  • improper deadstock management that brings scavengers to the farm

The risk of infection depends on whether there is direct or indirect contact with commercial poultry. To minimize this risk, all poultry premises should have enhanced levels of biosecurity to prevent the introduction and spread of avian influenza.

Ways to minimize risk include:

  • Prevent contact between domestic/commercial poultry and wild birds. Prevent contamination of equipment, feed and water by wild birds and their droppings. 
  • Prevent and manage conflicts between wild and domestic birds. Wild birds can be a source of disease coming onto your farm or for disease from your farm getting into the wild bird population. Making your operation unattractive to wild birds and practicing good exclusion techniques will minimize the potential of disease transfer.
  • Prevent contact between all birds (domestic or wild) and swine. Swine can also be infected with avian and human influenza strains, increasing the risk to poultry and public health.
  • Monitor the flock for signs of disease, increased illness or mortalities, and contact your veterinarian immediately if you have concerns. The veterinarian will submit appropriate samples to the Animal Health Laboratory at the University of Guelph. An early and accurate diagnosis is important. Veterinarians who suspect AI should immediately contact the Canadian Food Inspection Agency (CFIA). AI is a federally reportable disease in Canada and an immediately notifiable disease to the Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and the Ministry of Health.
  • Proper deadstock management to prevent scavenging of carcasses. Disease transfer can happen with avian species and mammalian species either as disease carriers or as vectors for disease. Scavenger species around a deadstock facility increases the risk of disease transfer from wild species to domestic species and vice versa. This risk also includes disease transmission from farm to farm by either wild or domestic scavengers.


Good biosecurity can help prevent disease. Read the following OMAFRA documents to learn more about enhanced biosecurity practices:

The Canadian Food Inspection Agency has resources on avian influenza and avian biosecurity.

What to do if you have a suspected outbreak of avian influenza on your farm

The Canadian Food Inspection Agency will quarantine your flock under the authority of the Health of Animals Act until confirmation of avian influenza (AI) has been verified. Once verified as a strain of concern, the CFIA will order the rest of the birds on the farm humanely euthanized and properly disposed of to limit the viral transmission.

Disposal of humanely euthanized birds and other potentially contaminated material

The Canadian Food Inspection Agency requires disposal of all contaminated material from the infected premises. Contaminated material could include:

  • bird carcasses
  • manure/litter
  • leftover feed
  • eggs (if applicable)

Contaminated material may also be treated using a verified biological heat treatment process to inactivate the AI virus. This process is achieved by creating compost windrows of the contaminated material inside the barn preferably, but this can be done outside also. The CFIA monitors the construction of the windrows and the compost process using temperature probes to confirm the materials have maintained a minimum time and temperature according to a hazard assessment.

Once the CFIA confirms these conditions, they release the material to the farmer for ongoing composting and ultimate disposal according to Ontario Regulation 106/09.

Though the material is not completely composted at this time, the AI virus is inactivated. The material is moved out of the barn to a selected site that meets specified provincial setbacks where the secondary stage of composting will occur. The material will continue to compost and be heat treated for several weeks or months until all soft tissue is consumed and the material resembles topsoil. At the end of the compost process, this material will be able to be applied to crop land in accordance with the provincial Nutrient Management Act.

Once the material is removed from the barns, the farmer starts to clean and disinfect (C&D) the barns and equipment to ensure there is no virus or infected material remaining. After the cleaning and disinfecting is completed, the premises will remain under CFIA quarantine for an additional 21 days.

Public health

Avian influenza currently poses a low human health risk, except for those in close contact with infected birds. However, the more widespread the virus, the greater the risk of recombination with other influenza strains which could result in the formation of a more serious influenza strain. For this reason, the World Health Organization and Health Canada have several recommendations to reduce this risk, including vaccinating poultry workers with the current human influenza vaccine.

Seasonal influenza vaccination

The Ministry of Health strongly recommends that all producers working with livestock or poultry, especially with birds or pigs, get the annual human influenza (flu) vaccine. It is free to all residents who work, live or attend school in Ontario.  It is free to all residents who work, live or attend school in Ontario. This includes:

  • poultry and pork producers and their employees
  • veterinarians
  • abattoir workers
  • those handling wild birds

Due to the evolving situation with avian influenza in cows and goats, Ontario is strongly recommending that all producers working with cows and goats also get the flu vaccine.

Infection control measures

Additional personal protective equipment (PPE) is recommended:

  • for people with occupational exposure to live birds that are showing signs of respiratory or neurological disease
  • where splash or aerosols will be generated (for example, using high pressure hoses or in ponds, or people working at the slaughter plants who are handling live birds) 
  • if  working in an area where avian influenza has been diagnosed in wild birds that are confined or in poultry

PPE should include:

  • fit-tested and seal-checked respirators (for example N95 or equipment with equivalent protection)
  • eye protection (such as tight-fitting non-vented safety goggles)
  • heavy duty rubber gloves when handling birds that can pierce skin with beak or claws, otherwise it is essential to wear rubber gloves or disposable gloves (such as latex or nitrile) for cleaning and sanitation procedures
  • impervious disposable gown or coveralls
  • disposable protective shoe/boot covers or rubber or polyurethane boots

You should be properly trained in:

  • fit-testing
  • wear and use of respirators
  • safe removal of respirators
  • proper disposal of disposable respirators or cleaning and disinfection of reusable respirators
  • medical contraindications to respirator use
  • procedures for the donning and doffing of PPE and its cleaning and sanitization or disposal

Hand hygiene must be performed before donning PPE, just prior to removing facial protection and after PPE has been completely doffed. Whenever possible, always work outdoors or in a well-ventilated area.

Please contact your local public health unit for more information on infection control measures.

If a producer develops an influenza-like illness while working with infected animals, they should immediately seek medical attention.

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