Something similar happened to me a couple of years back, late October. Loud, deliberate footsteps across the roof - not like an animal scrabbling about, more like something actually placing one foot in front of the other. My cat wouldn't move from under the bed until well past dawn.
What I found strange was the weight of it. The sound had real mass behind it, if that makes sense. Not a fox or a bird. I got my torch and went outside but there was nothing on the roof, nothing on the ground, no sign anything had been up there.
Your dog is the detail that gets me though. Animals don't spook easily without reason. What breed is it? And did the footsteps follow a particular path, like end to end, or was it more random movement? Would help to compare notes properly because I never really got an explanation for mine.