USDA monitors avian flu in dairy cattle across multiple U.S. States

By Andi Anderson

Since the first confirmed case of Highly-Pathological Avian Influenza (HPAI) in dairy cattle in March, the virus has spread to herds in 15 U.S. states, affecting 442 dairy farms. Originally found in wild birds and commonly associated with poultry, the virus was first detected in a dairy herd in Kansas.

Since then, cases have been confirmed in New Mexico, Ohio, Idaho, Michigan, North Carolina, Colorado, Iowa, Minnesota, South Dakota, California, Oklahoma, Utah, and Wyoming. The USDA provides a regularly updated webpage with diagnosis dates for each affected herd.

Symptoms in dairy cattle include reduced milk production, loss of appetite, and changes in manure consistency, primarily in late-stage lactating cows.

In contrast to poultry, which often succumb to the virus, dairy cows generally recover within two weeks if treated. However, reports indicate that some infected cows in five of the affected states have been culled due to illness.

To support ongoing research, the USDA's Animal and Plant Health Inspection Service (APHIS) has released genetic sequences of recent H5N1 and HPAI strains. APHIS encourages producers to share epidemiological data to help track and control the virus’s spread.

While the Centers for Disease Control and Prevention (CDC) considers human risk low, isolated cases of human infection have been reported, including 13 cases across Texas, Colorado, and Michigan, with one recent case in Missouri.

In response to HPAI’s presence in cattle, the USDA recently approved field testing of an H5N1 vaccine specifically for cattle, announced by Agriculture Secretary Tom Vilsack during an August farm show in Iowa.

The FDA has detected HPAI particles in pasteurized milk samples. In a public release, the agency confirmed that pasteurization likely inactivates the virus, ensuring the safety of milk products available in stores. 

However, the process does not entirely remove viral particles, underscoring the importance of preventive measures in dairy production.

With ongoing monitoring, USDA and FDA efforts aim to control HPAI’s spread in dairy cattle and ensure the safety of milk products for consumers.

Photo Credit: usda