(NDSU Ext.) – The first cases of Highly Pathogenic Avian Influenza (HPAI) in 2023 were confirmed in North Dakota in a Mallard duck in McHenry County on April 5 and in a commercial turkey flock in Dickey County on April 17.

“The primary carriers of avian influenza A are waterfowl, gulls, terns and shorebirds,” says Dr. Gerald Stokka, North Dakota State University Extension veterinarian and livestock stewardship specialist. “Wild birds can be infected without showing symptoms of the infection. While waterfowl are the primary carriers, positive cases are being documented in predatory birds and mammals.”

The best way to reduce the potential for transmission of HPAI is to reduce interaction between wildlife and domestic flocks.

“Wild birds and mammals, such as foxes, coyotes and raccoons, are transmission vectors to your domestic flocks,” says Dr. Stokka.

With wild birds and mammals testing positive for HPAI, hunters, homeowners and landowners should be aware of what steps to take if they see sick or deceased wildlife, advise NDSU Extension specialists.

While the transmission rate from animals to humans is low, it is a zoonotic disease, meaning it can be shared between species. Hunters participating in spring season should be aware of the risk of HPAI in wildlife and use measures to prevent transmission to domestic poultry flocks. Sick wildlife may display neurological symptoms.

“Dogs are not at high risk to contract the virus,” says Dr. Stokka. “However, there have been documented cases of dogs transmitting HPAI to domestic flocks. If your dog has interacted with wildlife, take measures to keep them away from poultry.”

“One of the first clinical signs of HPAI is sudden, unexplained death,” says Dr. Stokka. “Most HPAI cases are reporting a decline in water and feed consumption prior to the unexplained death.”

Decreased egg production and depression in layers may be another sign that birds are not feeling well. Purple or dry combs, being quieter than normal, frequent laying down and swelling around eyes are other symptoms birds may experience.