30/04/2022
This movement is caused by an unbalanced dog, i.e more rear angulation than front angles, and therefore unbalances the normal sequence of steps. It means that when dog was learning to walk right from first getting up and moving around in the whelping box as it started to increase the speed of moving, the rear feet would brush or hit the front foot, because the rear angle had more reach and the front foot was out of sequence because of the lack of angle, or short upper arm. So to stop tripping themselves up, they adapt a gait the twists the spine slightly off centre, to allow the rear foot to strike the ground on the inside of the front foot, and other side rear foot to strike on the outside of the other front foot. I have a slow motion video of a 12 week old puppy displaying this very thing. at a slower pace, it tracks true, as the handler increases the speed, and the puppy lengthens it stride, back foot hits the front foot because the sequence of steps is out of sync, and the the puppy immediately adapts a side winding gait to avoid the striking. It is not my picture , it is one I have 'lifted from FB so cannot publish, but can share privately if anyone is interested. for people who have a horse background will understand that this also happens in horses, and it is called 'Brushing" and is usually fixed by corrective shoeing, to make the rear hoof strike the ground sooner, thus putting the steps back into sync.