Dogs will at times move both legs on the same side forward at the same time. It's called pacing or ambling, and all dogs may move this way when they are tired. It apparently rests the muscles that are used at the normal trotting gait.

Pacing is often seen in sled dogs or in big working dogs like the Rottweiler. Dogs with too short a body for the length of their legs also tend to pace to keep from tripping when their back foot moves forward and encounters the front foot.

Author(s): McLennan, Bardi
Publication: Dog Fancy
Issue Date: May 1995