CWHC Ontario Wild Bird Avian Influenza Update

Highly pathogenic avian influenza continues to be a significant cause of morbidity and mortality for wildlife, since its first detection in Ontario in 2022.  This winter, the Canadian Wildlife Health Cooperative (CWHC) has been receiving reports of mortality events in wild birds throughout much of southern Ontario.  Highly pathogenic avian influenza (HPAIV) has been associated with many of these outbreaks, and we are continuing to detect HPAIV in wild birds across southern Ontario.  We are seeing mortality events associated with HPAIV in waterfowl, particularly Canada geese, and some scavenging species, including crows.  We are also seeing individual cases in numerous raptor species.  Prior to death, many of these birds are exhibiting neurological signs, including lack of coordination, swimming in circles, and tremors.  

We are continuing to monitor the situation and share information with provincial and federal partners. Data from cases submitted to the CWHC are used to inform ongoing surveillance and mitigation strategies and to help track the spread and evolution of HPAIV across Canada (e.g., Giacinti et al. 2024).  

In addition to causing disease in wild birds, HPAIV can cause disease in poultry, wild and domestic mammals, including cats, dogs, and livestock, and humans.  The risk for the general public is still considered to be low.

If you encounter sick or dead wildlife in Ontario, please contact the Canadian Wildlife Health Cooperative by phone (866-673-4781), email (on-nu@cwhc-rcsf.ca), or report online (https://www.cwhc-rcsf.ca/report_and_submit.php). For information about who to contact in other provinces and territories, please see this link.

We are grateful to all our submitters and project partners who support our surveillance activities, including the Animal Health Laboratory at theUniversity of Guelph, the Ontario Animal Health Network, the Canadian Food Inspection Agency, Environment and Climate Change Canada, and the Ontario Ministry of Natural Resources, Ontario Ministry of Health, and Ontario Ministry of Agriculture, Food, and Agribusiness. We also want to acknowledge the wildlife rehabilitation community, who continue to make important contributions to Ontario’s ongoing wildlife health surveillance activities.

For information on current HPAIV cases in wildlife please visit Canada’s HPAIV wildlife dashboard.

References

Giacinti et al. 2024. Avian influenza viruses in wild birds in Canada following incursions of highly pathogenic H5N1 virus from Eurasia in 2021–2022. mBio 15:e03203-23. https://doi.org/10.1128/mbio.03203-23

For additional information about avian influenza:

Human Health and Safety, Handling Guidance

• Wild birds and avian influenza – Handling guidelines – Public Health Agency of Canada (link) 
• Information about disease in people can be found on the Ontario Ministry of Health website. General information (link)

Avian Influenza and Wild Birds

• Avian influenza in wild birds and avian influenza – Environment and Climate Change Canada (link)

Avian Influenza and Domestic Poultry 

• Avian Influenza Information – Ontario Ministry of Agriculture, Food and Rural Affairs (link) 
• Information from CFIA about the status of ongoing avian influenza response by province (link)

Avian Influenza and other animals

• Information about animals susceptible to H5N1 highly pathogenic avian influenza (HPAI), including how to protect your pets (link)