My dog wakes up anxious pacing and wining

I would recommend a physical and lab work with your regular veterinarian to rule out medical ailments. That being said, he may be hearing some sounds that you are not which cause him anxiety. In our area people are already setting off fireworks and firecrackers in anticipation of the 4th of July. Alternatively, even though he is not that old, this may be early onset cognitive dysfunction. There are medications that will help with this problem. One of the first on the market, Anipryl, has shown some success at helping this type of behavior.