If anything physical it sounds more like stiff joints to me, it takes longer than a season to really lose enough muscle mass to effect a dog noticeably. The cold weather combined with less exercise can lead to temporary stiff joints, just like it does in humans. Nothing serious really. You can try giving some extra virgin coconut oil and unprocessed sea salt, but better weather and more frequent walks should take care of itself on its own.
But who knows, maybe he just wants to be held? :3 |