I have posted links in the past for dog friendly hiking, and ask you to comment on your experience with trails also.
This past weekend I went to the Vickory Creek Trail in Roswell. It is almost 5 miles of all dog friendly nature trails. What I liked about it was, although there are areas where the trail gets narrow, most of the time there is space to step off the trail if you need to give your dog extra space to pass other dogs. The trail is very well marked at each junction so you can make your hike as short, or as long as you like.
The trail has a covered bridge, civil war mill ruins, and a waterfall from the spillway dam. Unfortunately, we didn’t get to see everything because portions were closed for erosion work. But that didn’t take away from the fact that it is a great nature trail hike without having to drive to North Georgia. I would definitely do it again!