I asked my vet about that once because I saw Coco do that one time. She didn't do it again but I was curious so I asked her vet. He said it could happen in dogs kept in kennels or cages, it could just be a puppy silliness thing or more seriously, it could be a neurological issue. I don't want to worry anyone but just offering my vets advice. He told me if they don't grow out of it by 8-9 months, that it should get checked. Im sure it's nothing though and I bet it's cute to watch.
