Oklahoma has detected bird flu in a herd of dairy cattle, the state's agriculture department said on Friday, making it the 13th U.S. state to find the virus.

Dairy farm worker had mild symptoms and recovered after antiviral treatment
Shared equipment, workers may play roles in interstate spread
Canadian cases at nil as of mid-June according to CFIA testing
CFIA says continued negatives support view that HPAI has not reached Canadian dairy cows