 Just last week, more than 150 people in California were infected with salmonella from raw milk, marking the largest outbreak in the past decade linked to unpasteurized dairy. But raw milk can also expose you to viruses. The CDC recently reported that dairy cows in 13 states were infected with the H5N1 virus, also known as bird flu. And several studies have shown that when sick cows get milked, their bird flu can go along for the ride.