Highly pathogenic avian influenza (HPAI) outbreaks continue to be widespread across the U.S. in 2025, especially in layer flocks.
In the first month and a half of 2025, almost 28 million layers have been depopulated due to the disease, according to data from the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).
2025 layer HPAI cases have been found mostly in Ohio, at just under 10 million birds affected. Over half of those cases were detected in Mercer County, Ohio. Indiana follows Ohio at five cases confirmed and 6.6 million layers impacted this year, with most cases being in Jay County. Missouri has depopulated just under four million layers due to the disease, so far.
What happened in 2024?
HPAI was confirmed in 34 U.S. commercial egg layer flocks in 2024, totaling over 40 million layers lost to the virus.
December saw the most flocks affected at 15, impacting 14 million layers. Over eight million layers were lost in April, followed by approximately five million in May and four million in November.
What is the industry doing about it?
While egg producers have made many biosecurity improvements over the last couple of years to prevent the disease, it continues to affect the industry and is arguably getting worse. Egg producers are asking the USDA and universities for in depth epidemiological research to help determine the introduction source of the virus to improve prevention methods on layer farms.
This outbreak of avian influenza is impacting wild birds and mammal, making eradication more complicated. During the current outbreaks, almost 1,000 U.S. dairies have found positive cases in their herds.
A vaccine produced by animal health company Zoetis has recently received conditional approval from the USDA Center for Veterinary Biologics (CVB), however, final approval is still needed. While many industry groups support the use of the vaccine in the U.S., some have concerns that it would negatively impact trade.
View our continuing coverage of the global avian influenza situation.
To learn more about HPAI cases in commercial poultry flocks in the United States, Mexico and Canada, see an interactive map on WATTPoultry.com.
