Keep a LOT of coverage, shelters for them to hide under. I am down to 1 hen and one Mini Roo, freebie. I've heard the alarm call, stepped outside to find them hiding in a make-do shelter, on the back porch, I put up during for winter. Secure coops can be death traps, so I DON'T coop. OBVIOUSLY, it is up to YOU, You're the Mama.
If it's a rescue dog, IMHO, herding breeds are NOT always the best. Had family out here with a teenage Shep.pup who was trying to Herd My chickens! Lab mixes and if at all possible, one that has come back to the shelter; With the RIGHT love and care, they will be Devoted to you. Even if there is an Accident, I had to hang chick bodies from my Aust,/dane mix's collar, it seemed a game, He wanted to play. They will learn. Now days, I take out a hard boiled egg for a snack and have both chickens and dogs, coming around. Put a bit of wet food in the dog's dishes, dump a tiny bit for the chickens and so on.
Myself and at least one other person here, have set up places for the chickens to hide under for their own safety. When i am gone, i can come home to find my chickens here, dogs loose, yet at the same time, SOMEONE has been nibbling on my hay, Deer.
Good luck. I DON'T name my hens so it's doesn't throw me for a loop when one has gone missing. Oh, that's right, SOME will wander off to either Brood or whatever. They ARE animals and in the end, will do as they chose to do...