Idaho Dairy Industry Faces Quarantine Amid Bird Flu Outbreak

The Idaho dairy industry is grappling with an uptick in cases of highly pathogenic avian influenza (H5N1). The United States Department of Agriculture (USDA) confirmed 32 new cases in the last 30 days, raising the total to 162 since March 2024 when the outbreak was first detected. All recent cases have been confined to the dairy sector.

In response, the Idaho State Department of Agriculture (ISDA) has implemented stringent quarantine measures across the state. According to State Veterinarian Scott Leibsle, between 70 and 80 dairies remain under quarantine as of June 11, marking an unprecedented number of affected facilities in a single year. These quarantines are lifted only after two negative herd tests.

The outbreak does not pose a risk to the commercial milk supply or human health. The avian influenza virus is effectively neutralized through standard pasteurization, allowing milk from quarantined dairies to be processed safely. This ensures that revenue streams for affected producers remain intact.

Animal health experts have identified the movement of cows and calves between facilities as the primary transmission vector, rather than migratory waterfowl. This is further complicated by the absence of a vaccine for the strain. Symptoms in infected herds include reduced milk production, altered milk consistency, fever, and appetite loss.

The state expects that rising summer temperatures will help slow the virus's spread, based on trends from previous outbreaks. In the meantime, officials are urging dairy operators to maintain strict biosecurity measures, isolate new livestock for three to four weeks, and exercise caution when acquiring animals.