November 24, 2025

Following an investigation by the Michigan Department of Agriculture and Rural Development (MDARD), the Michigan State University Veterinary Diagnostic Laboratory has detected the presence of highly pathogenic avian influenza (HPAI) in a backyard flock from Ontonagon County. This is the first case of HPAI in poultry from an Ontonagon County flock since the virus was first detected in Michigan in 2022, and the first case in Michigan’s Upper Peninsula since the spring of 2022 when four infected backyard flocks were found in Menominee County. Adhering to biosecurity measures and using personal protective equipment (PPE) continue to be vital in helping ensure the health of Michigan’s domestic animals and the general public.

HPAI is a highly contagious virus that can be spread in various ways from flock to flock, including by wild birds, through contact with infected animals, by equipment, and on the clothing and shoes of caretakers.