Any dog is safe to have around chickens if it's smart enough to learn what's yours and that what's yours is not to be bothered, especially your other animals. I seriously doubt that our two corgis would ever try to protect one of our chickens, but I'm 99.99% sure that they would never intentionally hurt one of them. There are lots of dogs though that if introduced to small chicks and made to understand that those chicks are theirs too and part of your family, they will protect them.