I made an enclosed run so predators aren't an issue. Use a strong metal mesh for the walls of the enclosure. Dig it down at least a foot to prevent burrowing, but you may also want to bury a mesh floor if you have lots of predators. With an enclosed run, the chickens can get in/out of the coop for exercise and you can leave them for a few days if necessary. If you just have a coop, you'll need to let them out each day and lock them up at night for predators. I don't have experience with dogs or other guards. I put a lot of effort into my coop/run so that I can leave them for a week at a time (or longer if food/water is stocked). The only daily item that needs taken care of is removing eggs, and I can usually get a neighbor to agree to free eggs.