Learn where Highly Pathogenic Avian Influenza is spreading among dairy cattle

Two more states have earned the dubious distinction of confirming an outbreak of avian influenza in dairy cattle. As of Thursday, this list includes one Idaho herd, three Kansas herds, two Michigan herds, five New Mexico herds, one Ohio herd, and 10 Texas herds, Added to the list are one South Dakota herd and one North Carolina herd.

News of the virus first infecting dairy cattle was confirmed by the U.S. Department of Agriculture (USDA) on March 25 that for the first time, influenza A had been reported in ruminants.

The South Dakota Department of Agriculture and Natural Resources reported its first avian influenza, or bird flu, was detected in a South Dakota dairy cattle herd.

DANR and the state Animal Industry Board, a board assigned to the state ag agency, announced Thursday the U.S. Department of Agriculture's National Veterinary Services Laboratory confirmed a positive detection of the virus in the herd April 9. This is the first confirmed case of bird flu in a dairy farm in South Dakota, Argus Leader reported.

The virus was also detected in a dairy herd in North Carolina, said Steve Troxler, North Carolina's agriculture commissioner in a statement.

Virus linked back to Texas outbreak?

State officials in at least four states ‒ North Carolina, Michigan, Idaho and Ohio ‒ reported that infections in dairy cows from their states traced back to Texas dairy herds. Owners of infected cows in those states said they unknowingly introduced the virus into their herds after purchasing cows from farms involved in the Texas outbreak.

While previous outbreaks reported that the virus had struck older cows in mid-lactation, DTN reports that North Carolina officials stated the cows that tested positive were younger cows.

Animal health officials stress that the outbreak is evolving as they search for answers. Here is a timeline of events.

April 9, 2024

U.S. Department of Agriculture's National Veterinary Services Laboratory confirmed a positive detection of the highly pathogenic avian influenza virus in a dairy herd in South Dakota and North Carolina on April 9. This is the first confirmed case of bird flu in a dairy farm in either state. .

April 4, 2024

The Ohio Department of Agriculture receives confirmation from the USDA’s National Veterinary Services Laboratory (NVSL) that the highly pathogenic avian influenza (HPAI) has been detected in a Wood County dairy cattle herd in Ohio. Officials say the Ohio farm introduced cows into the herd from a Texas dairy on March 8.

April 1, 2024

The CDC reports that a Texas farmworker having direct contact with infected cows has tested positive for the HPAI virus.  The employ is being treated with an antiviral drug and has exhibited only symptoms of pink eye. CDC and USDA officials stress that the risk to the public remains low.

April 1, 2024

Within days, highly pathogenic avian flu is identified in two dairy herds from New Mexico and an additional herd in Kansas. The disease is also confirmed for the first time in the state of Idaho in a herd located on the Canadian border.

March 29, 2024

USDA’s National Veterinary Services Laboratories (NVSL) has now also confirmed the presence of HPAI in a Michigan dairy herd that had recently received cows from Texas.

March 27, 2024

Samples collected from three additional herds in the Texas panhandle test positive for HPAI.

March 25, 2024

Tests on raw milk and nasal swabs from sick cows from two dairy farms in Kansas and two in Texas test positive for highly pathogenic avian influenza (HPAI). Based on findings from Texas, the detections appear to have been introduced by wild birds.

March 22, 2024

American officials published an urgent announcement that dairy cows in Texas, Kansas, and New Mexico were falling sick. Animal health officials noted that the cows had low appetites, and produced less milk than normal. Some farms also discovered wild bird carcasses on their grounds.

March 20, 2024

Minnesota Board of Animal Health (MBAH) reported that a juvenile goat on a Minnesota farm tested positive for highly pathogenic avian influenza (HPAI). This marks the first U.S. case of the virus in a domestic ruminant. Poultry on the Stevens County property, including chickens and ducks, was quarantined from a previous HPAI detection.

MORE: Navigating bird flu in cows: What Wisconsin dairy farmers need to know