SIOUX FALLS, S.D.(KELO)- Spring migration is underway, and that brings the threat of the highly contagious bird flu…and this spring there’s a twist.

In addition to threatening domestic poultry flocks, a couple of southern states say the flu virus has also been found in swine and dairy herds.

South Dakota state veterinarian Beth Thompson says her department and industry leaders are keeping a watchful eye on their flocks and herds.

Thompson says there’s no threat to humans, and that the food supply is safe.