On February 11, 2025 the Arizona Department of Agriculture (AZDA), working in conjunction with the United States Department of Agriculture (USDA), confirmed Arizona’s first identified H5N1 avian influenza detection in milk produced by a dairy herd in Maricopa County. As a protective measure, the facility is currently under quarantine. Unlike other detections involving B3.13 H5N1, cattle have not yet displayed signs of illness with this particular D1.1, but if clinical symptoms become evident, cattle will be isolated from the main herd.

Coconino County Health and Human Services (CCHHS) has confirmed that H5 avian influenza has been detected in wastewater sampling. The specimens were collected at the Rio De Flag Water Reclamation Plant and the Wildcat Hill Water Reclamation Plant. The source of the virus is suspected to be from chickens and wild birds, however other sources cannot be ruled out. There are no reports of human or animal H5 cases in Coconino County.