The newly reported H5N9 strain was found Monday at a duck farm in Merced County, California, according to the World Organization for Animal Health. The Paris-based organization that studies animal diseases said it's the first verified U.S. case of H5N9 in poultry. The organization said the more common strain H5N1 was also found.

The CDC has confirmed a new human H5N1 bird flu case in California, raising the US total to 67. Most cases involve farm workers exposed to sick animals. The CDC urges rapid testing, antiviral treatments,

According to the Centers for Disease Control and Prevention, bird flu outbreaks have impacted poultry in 51 states, while the virus has been detected in dairy cows across 16 states.