Faced with the rapid spread of avian flu through California dairies, health officials are now doing weekly testing of every dairy farm in the state — expanding initial efforts amid new evidence that some infections are going undetected and there may be unknown paths of transmission.

California officials have declared a state of emergency over the spread of bird flu, which is tearing through dairy cows in that state and causing sporadic illnesses in people in the U.S.

The California Department of Food and Agriculture has issued a statewide recall of raw milk produced and packaged by Valley Milk Simply Bottled after H5N1 bird flu virus was found in samples from a bulk tank at the company’s dairy farm.

The billboard campaign encourages farmers who might have been affected by the bird flu to transition to "other plant-based source of livelihood."

Officials have discovered the virus in 645 dairy herds, more than in any other state so far. In a stark acknowledgment of the increasing seriousness of bird flu’s spread, Gov. Gavin Newsom of California declared on Wednesday that the outbreak of infections among the state’s dairy cattle constituted an emergency.

The County of San Diego is warning the public to not eat or drink raw milk products or give them to their pets after Gov. Gavin Newsom declared a State of Emergency due to a rise in H5N1, or bird flu,