So, I woke up this morning, and Maximus was lying on the floor ..... next thing I know he stands up and is unable to walk. His back <L> leg he lifts off the ground and is hobbling along on 3 legs. OMG ! WHAT on earth happened ! Should I rush him to the vet? or maybe he just slept wrong on his leg, or it's just stiff, or I don't know what to do here .............