As contradictory and confusing bird flu test results come back from various county and state agencies, the state's agriculture department has instructed raw milk producer Raw Farm to withhold sales.

The detection of bird flu virus this week in a batch of unpasteurized milk sold in California underscores what health experts say are the known and potential risks of the products.

H5 bird flu, a type of avian influenza, has infected dozens of people in the U.S., and spread to seven states and Canada this year.As concern grows over whether it could lead to another pandemic or lockdown,