Could be, the hounds can certainly rattle the walls when they get wound up. My pictures are never straight, I don't fight it anymore. just accept it as the way the world will be
To us a house seems immovable but I think it is constantly shivering or tweaking plus I think every time you open and close a door or go up and down stairs, you send vibrations and air currents through out the house. Little by little it affects the pictures on the wall.