The ongoing H5N1 avian influenza outbreaks in both commercial and backyard poultry across the United States are steadily escalating. The Animal and Plant Health Inspection Service (APHIS) of the US Department of Agriculture (USDA) has recently identified additional cases in domestic cats.

APHIS has also reported five new detections of H5N1 in dairy cattle, all located in California, alongside over 50 cases confirmed in wild birds across various states.

Poultry Farms Affected

In the past two days, APHIS has documented the presence of the virus in multiple poultry flocks across seven states, highlighting significant impacts on several commercial operations.

Ohio has seen the worst of the outbreaks, with confirmations on four layer farms and three turkey farms, while Pennsylvania reports five additional commercial farms impacted. Further west, two farms in Missouri, including a turkey and a broiler farm, have also experienced outbreaks.

Additionally, federal authorities have confirmed outbreaks in two more live bird markets in New York City’s Queens and Bronx boroughs. The earlier detections in live markets across Queens, the Bronx, and Brooklyn prompted the state governor to announce a temporary closure of these markets in New York City and surrounding counties.

APHIS has also reported new cases in backyard flocks located in Louisiana’s Calcasieu County, as well as areas in Washington and Connecticut.

Since H5N1 was first detected in U.S. poultry in early 2022, there have been unprecedented losses, accounting for over 157.7 million birds across all 50 states and Puerto Rico.

As detections persist in both domestic and wild bird populations, the Michigan Department of Agriculture and Rural Development has stressed the importance of ongoing protective measures for poultry owners, especially with wild birds beginning their spring migration.

Officials indicated that while it’s difficult to predict the spring situation, it is clear that this disease will continue to pose a threat to Michigan’s animal agriculture. Taking preventive action to safeguard domestic birds from highly pathogenic avian influenza (HPAI) is crucial.

Increased Cases in Cattle and Wild Birds

In related news, APHIS has reported five additional detections in dairy cattle, all from California. This increases the national total to 962, with California alone reporting 744 cases.

The virus continues to significantly impact wild bird populations, as more than 50 additional H5N1 confirmations were reported today, affecting various species, including gulls, geese, ducks, and raptors. The list includes both hunter-harvested and live-sampled waterfowl from states such as Louisiana, Indiana, Arizona, Nebraska, Oregon, and Michigan.

Domestic Cats Affected in Three States

APHIS has confirmed three more cases of H5N1 in domestic cats. Among these is an infected stray cat from San Mateo County, California, which was noted by county officials on February 6. This cat was brought in for treatment by a family in Half Moon Bay after showing symptoms, but unfortunately, it was euthanized due to its condition. The mode of transmission remains unknown.

Additionally, another detection involves a cat from Flathead County, Montana, sampled back on December 5, 2024, as well as a cat from Multnomah County, Oregon, sampled on February 3.