H5N1 is an emerging disease in Minnesota's dairy herds. The virus was first detected in June 2024 in a Benton County dairy herd. H5N1 is the same virus that causes highly pathogenic avian influenza in poultry. Spread of the virus between states is tied to cattle movements, and local spread appears to mostly be connected to infected milk and the virus being spread both directly and indirectly to other locations. The USDA is tracking the latest cases across the country and new epidemiological discoveries from the outbreak on its website. Biosecurity remains the strongest measure to prevent the spread of this and other diseases. The most reported clinical signs from affected herds are abnormal lactation, decreased feed consumption, and thickened or clotted milk. Producers should also lookout for the following and contact their veterinarian if cows exhibit these signs:
- Decreased herd level milk production.
- Sudden drop in production with some severely impacted cows experiencing thicker, concentrated, colostrum‐like milk.
- Decrease in feed consumption with a simultaneous drop in rumen motility.
- Abnormal tacky or loose feces.
- Lethargy, dehydration, and fever.