Amid uptick in poultry detections, Minnesota reports first case of H5N1 influenza in a dairy herd

Publish Date

H5N1 influenza, the same virus that causes HPAI in poultry, has been confirmed in a Benton County dairy herd. Over the weekend the producer noticed clinical signs in only a handful of cows, the next day more than 40 cows had signs of fever. Samples collected from sick cows in the herd on Monday were sent to the University of Minnesota Veterinary Diagnostic Laboratory where the virus was detected. The USDA’s National Veterinary Services Laboratories confirmed the results last night. According to the Centers for Disease Control and Prevention (CDC), pasteurized dairy remains safe to consume.

“We knew it was only a matter of time before this detection would reach our doorstep,” said State Veterinarian, Dr. Brian Hoefs. “It’s important for dairy farmers to follow the example of this herd and test sick cows. The more the animal health community can learn about this virus today through testing and research, the better we can equip ourselves to prevent infections tomorrow.”

Dairy farmers should monitor their herd and contact their veterinarian immediately if cows appear sick. H5N1 clinical signs in dairy mostly affect late-stage lactating cows and include fever, a drop in milk production, loss of appetite, and changes in manure consistency. No matter the H5N1 status of a herd, biosecurity can reduce the risk of disease spreading onto or off farms:

  • Consider stopping or delaying any cow movements and test for H5N1 before you move animals.
  • Milk any sick cows last, after your healthy herd.
  • Keep feed covered and clean up feed spills immediately.
  • Provide cows a clean source of water kept secure from wildlife, especially waterfowl.
  • Talk to your herd veterinarian if you notice any signs of illness in your animals.

Dairy farms are always required to dispose of milk from sick animals to remove it from the milk supply. In addition to the affected herd disposing of milk from sick cows and isolating them, the Board quarantined the herd for 30 days to reduce the risk of disease spread off the farm. After 30 days from the last positive test result, the herd can be retested to be released from the quarantine.

The risk to the public from this virus remains low at this time. People who work with or have direct contact with infected animals could be at risk of getting sick. The Board is working closely with the Minnesota Department of Health (MDH) on this response. MDH’s role is to monitor the health of people who have direct contact with infected animals and provide public health information and recommendations.

CDC recommends people who work with infected or potentially infected animals wear personal protective equipment (PPE) to help protect themselves from infection. More information is available on CDC’s website. Farmers can request PPE from MDH. Symptoms of avian influenza in people may include cough, sore throat, fever, red/watery eyes or discharge from the eyes. People who have questions can contact MDH at 651-201-5414.

The Board will report any new detections and updates on cow cases in Minnesota on its website. The Board has also seen a recent rise in poultry cases in the state with eight sites positive for the virus in May. Early investigations from some of those sites reveal birds were infected with the same virus strain detected in cows across the country.