WHY ARE YOU RUNNING?

It's ok and thank you for the feedback 😊

Apologies for summoning the wall of text, However I do hope some of my criticism can help.

Aside from that I say you did a good job in choosing to do a frame by frame instead of just copying a frame and editing it, I also think you did a good job with calculating how the run effects the body neck and head of the dog as shown with the dogs head bobbing

Finally, I suggest you pay attention to issues with the fill tool, if you look closely at the animation now you can see white spots that the fill tool missed, remember that fill tool isn’t perfect and sometimes you gotta manually fix a few spots.