re: Elderly dog barking at night, pacing, and seeming restless - any pet owners with advice?

Reading through everyone's responses- lots of good info and could be any of the issues. My elderly large dog had vestibular and paced and lost control of his poop. My little man of 15 goes through phases where he does exactly what yours does. There is not a real medical issue- guessing some pain, stomach discomfort and possibly dementia. I use an anti-inflammatory and sometimes gaberpentin. Don't lose hope yet.