I have only LF of the RIR, wyandotte etc, and they stay within 150 feet of their coop; I have heard some breeds are good wanderers and cover a greater distance. Some breeds tolerate being cooped up and other breeds do not.
Fencing is very helpful and has many purposes therefore comes in a lot of choices to suit your purpose. Fencing is an extensive subject. Sometimes fencing is to keep animals in, sometimes it's to keep a predator out. Electric fencing works only if the animal is trained to understand the ZAP factor; otherwise the uninitated will run right thru it. OFten electric netting is used inside of a more substantial fencing to subdivide areas. Fox are clever and fast; a grab 'n go sort. Dogs are similar and can be kept out with the same protection as you would use for a fox.
Covered run. If you want the absolute best protection, build a covered run; these can be built flimsy or like Fort Knox and in between, whatever suits your needs. THe better the protection, the more expensive the materials.
I lost another chicken yesterday to a coyote, 10 feet from the house. Of course the chicken had failed to go to the coop for the night and was easy pickings. So I put up a 4 foot woven wire fence around that chicken area to keep out the coyote and to guide the coyote on his way. THere is a trail across our property used by the deer and coyote that passes very near this coop and our house. The fence will keep him on the trail. No more Grab 'n Go breakfast for the coyotes.
Maybe a 4 foot fence is an option for you. Chickens can fly over it, but it will keep the canines out.
GL