Liz Buchanan BVSc MRCVS
Hello! The most common reason for this, is pain. It is not unusual for dogs to experience mild to moderate pain at night and not during the day. During daytime, life is full of excitement and distrations, but at night, they are alone with their pain. I wonder about things like pancreatitis, arthritis pain and so on (think how joints get stiff later, not while doing the exercise).