We have a greyhound Pitbull mix. She is about 6 years old and I can say that being gentle with / ignoring our chickens just came naturally to her. We had a pop-up puppy playpen that we used as our containment when they were very young. We had it in our family room / TV room so she was just used to their smells and sounds. When we finally let them outside she always wanted to lay out in the yard and keep an eye on them. Lucky enough, she even tries to chase away cats and squirrels that try to venture into the yard. Like I said, we were sincerely blessed that there was no training necessary. The chickens don't seem to mind her at all. Whether she's napping in the grass or walking around, they could kind of care less. And when our neighbors dogs get loud and riled up they actually run to her as kind of a sense of security.