I could be Alpha till Im blue in the face . . .
Some breeds have been specifically bred to be independent and self-reliant, like my JRT who was made to be fearless and smart enough to get a fox or badger out of a hole, once he is in kill mode he dont stop.
No matter how much I yell or try to stop him, he will kill if given the chance and come bring the animal and lay it at my feet and look up at me sooo proud of himself . . . "look what I did for you dad, I killed this nasty old bird".
I cant fault him for that, thats what he does.
Im the one who wanted him, and Im the one who wants chickens.
I just do what I gotta do to make it work.
For me, that means using a shock collar, like I said, he was a quick study with it, and these days its more a preventative measure.
He knows what could happen when that collar is on him.
But, on the other hand, I dont need to worry about raccoons or skunks or rats or anything like that, he does his job well.
Like someone else said, even well-meaning wanting-to-play dogs can "love" a chicken to death . . .
Some dogs work with chickens, some dont.
If you have any doubts at all about your dog, just be safe rather than sorry and keep it well separated from your chickens.