A robot which gently brushes the underside of a paw with a feather or a brush.  It would be similar to a scalp massager but easier to construct & less prone to injury.  It would sit on the floor.  It might be a practical use of sonar.  The key to all brushing robots is the ability to apply a constant force for all distances.  It could be just an excuse to build a robot arm. 

A lion would want to use a paw massager while standing. It makes it tricky to position the paw. It's almost easier to have the massager face forward & the paw to face back while sitting on the floor.

The easiest way for a robot to access body parts higher up is to mount it on a telescoping pole from the floor to ceiling. Lions have used telescoping poles to store stuff near the ceiling without drilling.