"And the one we have right now is highly aggressive and especially extremely devastating to the poultry industry. It can kill almost all the birds in a flock very quickly when it gets into it."

Bird flu can also cause respiratory and classic flu-like symptoms, including cough, runny nose, fever, sore throat, body aches, headaches, fatigue, shortness of breath, and pneumonia, the CDC says. Some people in the U.S. who have caught bird flu have experienced respiratory symptoms as well.

A wildlife sanctuary in Cornwall with more than 1,300 exotic and rare birds is on alert after an outbreak of bird flu was confirmed in a nearby village. Keepers at Paradise Park in Hayle have introduced strict biosecurity measures to reduce the possibility of the disease infecting the bird collection after the highly pathogenic avian influenza (HPAI) H5N1 was found on a poultry farm near Rosudgeon.