Add side-to-side movement to the tail:
1 Make sure Auto Key and Angle Snap are both on.2 Activate the Top viewport, if it isn’t active already.3 At frame 1, select the lowest link of the tail, Bip01 Tail.4 Rotate Bip01 Tail to the dog’s left, – 15 degrees in the local Y axis.5 Rotate the remaining three tail links in the opposite direction,
to counter the side-to-side motion of the spine.Animating a Quadruped Walk | 1037