Avian Flu Update: CFIA Reports Total of 16 Million Cases since 2022 — How to Spot Symptoms

Canada's ongoing avian influenza outbreak has now affected an estimated 16.59 million birds nationwide, according to the latest update from the Canadian Food Inspection Agency (CFIA) as of November 26, 2025. The figure includes birds that died from infection and those humanely depopulated to prevent further spread.

Since detections began accelerating in 2022, the virus has continued resurfacing across multiple provinces, prompting strengthened biosecurity measures and renewed warnings to commercial and backyard bird owners.

READ MORE: The Next Pandemic? Bird Flu 'H5' Seen As Bigger Threat Than Covid-19

READ MORE: Panic Warning As Washington Man Dies From 'Terrifying' New Bird Flu

Canada Reports Over 16 Million Birds Impacted Since 2022

CFIA data shows that British Columbia remains the most impacted province, with approximately 9.75 million birds affected, followed by Alberta at 2.48 million and Quebec at 1.47 million. In total, 73 premises are currently under investigation across the country, while more than 540 previously infected sites have been released from quarantine.

The agency emphasises that both highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) subtype H5 remain active in domestic flocks. Although HPAI detected in US dairy cattle has raised concerns internationally, CFIA confirms that this strain has not been identified in Canadian poultry.

Authorities continue to advise farmers to tighten biosecurity, report sick birds immediately, and avoid interactions between domestic flocks and wild waterfowl, which serve as natural reservoirs for the virus.

Symptoms of Avian Flu: What Farmers Should Watch For

The CFIA highlights several key symptoms that can signal HPAI infection in domestic birds:

Common clinical signs include:

• A sudden drop in egg production, including soft-shelled or shell-less eggs
• Quietness, extreme lethargy or depression
• Diarrhoea
• Swelling around the head, eyes, wattles and combs
• Haemorrhages on the hocks
• Rapid and unexplained mortality

The incubation period ranges from two to fourteen days. Because symptoms mimic other serious poultry diseases, such as Velogenic Newcastle Disease, laboratory testing is required for confirmation.

There is no treatment once a bird becomes infected. Vaccination, where permitted, may reduce spread but does not prevent the virus from circulating within a flock.

Why H5N1, H5N2 and H5N5 Matter — and How the Virus Spreads

Most strains of avian influenza are low pathogenic, but H5 and H7 subtypes have the ability to mutate into highly pathogenic forms after infecting domestic birds. Canada's current outbreak is dominated by the H5N1 subtype, though H5N2 was detected in British Columbia in November 2024 and H5N5 in Newfoundland and Labrador in February 2025 — both highly pathogenic.

Experts note:

• Wild waterfowl remain the primary carriers of avian influenza viruses.
• The virus spreads easily through contaminated clothing, manure, equipment, vehicles, feed and water.
• People working with poultry should use protective equipment, as rare human infections have been documented globally.

The World Organisation for Animal Health (WOAH) warns that the continued spread of H5N1 among mammals increases concern about viral adaptation, emphasising the need for surveillance, reporting and strict biosecurity.

What This Means for Bird Owners

CFIA urges all poultry owners, both commercial and backyard, to:

• Report unusual bird deaths or symptoms
• Avoid contact between flocks and wild birds
• Clean and disinfect equipment
• Restrict access to poultry barns
• Follow instructions on quarantines and movement controls

The agency reminds travellers returning to Canada to avoid contact with birds for several days and declare all poultry products at entry points, as the virus can cling to clothing, shoes and equipment.

With millions of birds already impacted and detections continuing across the country, CFIA maintains that rapid reporting and heightened prevention remain essential in controlling Canada's largest bird flu event on record.