I think you are looking to raise roadrunners, not chickens! Unfortunately chickens are at the bottom of the food chain because they can't get away from many predators. Knowing this, it is our job, as owners, to protect them since they don't do a very good job of protecting themselves. Good fencing will go a long way to protecting your hens from dogs. I use electric net fencing, and that has allowed my chickens to live in relative safety from dogs, foxes, raccoons, bobcat and bears.
On an interesting note, I have had white leghorns, rhode island reds, barred rocks and americanas. All have been taken by predators (before the fencing) except the white leghorns. I'm not sure if that's because they are more aware of their surroundings, more flighty, or simply smaller bids, and the predators go for the bigger meals!