You can argue with whether or not the government overreacted, but it absolutely wasn't a HOAX.
It's called bird flu, because its specific to birds, at least for now. We have had other bird flus (also called Avian Flu) that mutate and then spread to other animals who have not seen this particular strain of flu before, thus making it a novel flu meaning there is no herd immunity. That means it could possibly spread more rapidly and have potential to be more virulent.