HPAI in backyard pig in Oregon

November 4, 2024

Please see the below message from Drs Marianne Parent and Barb Wilhelm, Western Canadian Animal Health Network.

Many of you likely heard about the recent positive case of highly pathogenic influenza A(H5N1) in a backyard pig in Oregon. Here are some takeaways:

-The pig was from a small herd of swine (5pigs) that shared water sources, housing and equipment with sheep, goats, and a small poultry flock.
-The poultry tested positive for H5N1 and were de-populated.

-Having been noted to be scavenging on dead wild birds, the pigs were euthanized and tested out of an abundance of caution.

-Sheep and goats at the farm are under surveillance.
-The Influenza A strain isolated from the infected poultry on-farm is the circulating wild bird strain, NOT the one occurring in dairy cattle in the US.

A western Canadian veterinary virologist described the situation this way: “think of the backyard pig in this case as another scavenger mammal! We have found H5N1 in other species (e.g. skunks) in the west, and this detection in the backyard pig in Oregon is not surprising, given the circumstances”. It was also reiterated that infection of pigs with H5N1 in the lab has been extremely difficult to produce via the aerosol route.

We continue to recommend the application of biosecurity measures to prevent the transmission of HPAI from wildfowl to small flocks and small herds of swine. In addition to minimizing the access of wildfowl to livestock, their environment, and water sources, precautions should be taken to prevent outside-backyard pigs from scavenging on dead poultry or wildfowl.

Thanks for your time, and have a good weekend,

Drs Marianne Parent and Barb Wilhelm,

Western Canadian Animal Health Network