The Bouncing Dog of Washington Square Park

I am not the kind of person who usually watches Stupid Pet Trick-type videos, and certainly not the kind of person who inflicts said videos on other people, but:

In this case, I cannot resist. The bouncing dog in this video is named Moishe and belongs to my cousin Barbara Koltuv, who is the person on the other end of the leash, taking Moishe for a bounce in Washington Square Park in New York. I finally stopped laughing about the 17th time I watched the video. Barbara says the bouncing is always accompanied by barking, but otherwise it’s hard to say what causes the bouncing itself. I feel that the guitar music in the background only heightens the strange effect.