At which point he unexpectedly found himself gazing at the world from a significantly different vantage point.
He still stood on all fours, but very different fours they were. He was more naked than even when his master had taken to shaving him in anticipation of the hottest months of the summer. Gray-tinged bare flesh met his startled gaze. Sitting back, he found his head and upper body rising of their own accord, until he was standing, yes standing, on his two hind legs. His eyes looked down at the world from a height considerably greater than before. Stunned quite beyond anything in his open, good-natured experience, he let out a howl of surprise.
To read more, look for Kingdoms of Light by Alan Dean Foster.