The Minnesota Board of Animal Health (MBAH) has confirmed H5N1 influenza in a dairy herd in Stearns County. The virus was detected through the state’s milk surveillance program, with the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratories confirming the results on March 21. The affected herd is now under quarantine until testing confirms the infection has cleared.
Officials emphasize that the public milk supply remains safe. All commercially sold milk undergoes pasteurization, a process proven to eliminate viruses and bacteria, including H5N1.
Quarantine and Testing Measures
While under quarantine, the herd can apply for movement permits for animals and byproducts like waste milk and manure. Milk intended for pasteurization does not require a permit and can still be processed to maintain business operations while minimizing disease spread.
The Minnesota Department of Agriculture (MDA) continues its monthly testing of raw, pre-pasteurized milk samples from the state’s approximately 1,600 dairy farms. These samples are analyzed at the Minnesota Veterinary Diagnostic Laboratory at the University of Minnesota to monitor for H5N1. Identifying affected herds is crucial for controlling the virus and protecting animal and public health, according to MDA Commissioner Thom Petersen.
Response and Public Health Monitoring
When a case is detected, the Board of Animal Health assigns a case manager to the affected farm, enforces quarantine measures, and guides producers through the response process. The Minnesota Department of Health (MDH) also monitors individuals who have direct contact with infected animals, offering testing, antiviral treatments, and personal protective equipment (PPE) as needed.
Health officials state that the overall risk to the public remains low, with the highest risk posed to those in direct contact with infected livestock.
Symptoms and Biosecurity Measures
Farmers are encouraged to monitor their herds closely and report any signs of illness to a veterinarian. Symptoms in dairy cattle, particularly late-stage lactating cows, may include:
- Fever
- Decreased milk production
- Loss of appetite
- Changes in manure consistency
To prevent the spread of H5N1, dairy farms are urged to implement strict biosecurity measures, including:
- Keeping a visitor log and enforcing farm biosecurity protocols.
- Milking sick cows last, after the healthy herd.
- Protecting feed from contamination and cleaning up spills promptly.
- Ensuring livestock have access to clean water, safeguarded from wildlife, especially waterfowl.
Milk from sick cows must be discarded to prevent contamination. Affected herds must complete three consecutive negative milk tests before quarantine restrictions can be lifted.
Additional Resources
Farmers in need of PPE can request supplies from MDH if they cannot acquire them through regular sources. Those with concerns about avian influenza and human health can contact MDH at 651-201-5414.
The Minnesota Board of Animal Health will continue reporting new detections and updates on its website. The Stearns County herd was previously infected in July 2024 and will remain categorized as “Stearns MN 010” on the state’s online dashboard, with any new developments updated accordingly.
For the official announcement, visit: Minnesota Board of Animal Health.
