I lucked out with my GSD girl and my aussie/heeler boy. Neither bothers the chickens. Well the gsd will lick their butts give the chance and them standing still. I've been teaching them both to help me herd the chickens when needed. They chase off any other birds. You'll see the chickens chase a little thief bird out of their run and then my little boy waiting to get it farther away. I can let the birds free range with the dogs out. Dogs help discourage eagles and hawks and ignore the chickens even if they are hiding under them.
My 15 year old schipperke was not trustworthy. She wanted the chickens and was going to get them, a feather at a time if needed. She was old, slow, couldn't hear and blind in one eye and she was still determined. She was a good mouser in her youth and always had a strong prey drive.