Avian Influenza Detections Drop, But Fall Migration Looms

By Bernt Nelson

Over 175 million birds and 1,075 dairy herds have been affected by the current strain of Highly Pathogenic Avian Influenza (HPAI) since it began in February 2022. Detections of HPAI in both poultry and dairy cattle have slowed over the summer months with zero detections in commercial poultry flocks and just one dairy herd detection in the last 30 days. This Market Intel provides an update on the status of HPAI and what to watch for as the fall migration season approaches. Migratory birds moving south along flyways are the most likely to spread HPAI, which survives better in cool conditions, making fall a likely time for HPAI flare-ups.

The Outbreak

Poultry

Since the first detection of the current HPAI strain on Feb. 8, 2022, there have been 1,710 detections of HPAI in 50 states and one territory, affecting nearly 175 million birds. The virus caused the most production loss in turkeys and egg layers due to their close proximity to the Central and Pacific flyways where HPAI is more prevalent. Broiler flocks (chickens raised for meat), while impacted, are raised further from those flyways and have benefited from lower infection rates.

Dairy Cattle

The first detection of HPAI on a dairy farm occurred in March 2024. Since then, HPAI has been confirmed in 1,075 dairy herds in 18 states. Over 72%, or 777, of premises with positive detections were in California. Factors like geographic location and shared employees, equipment and vehicles are risk factors for spreading the virus among dairy farms. The last detection of HPAI for dairy and poultry was a dairy herd that tested positive in California on Aug. 1, 2025.