I have a 7yr old lab who has lost her lifetime companion, a 17yr old toy poodle. She rarely ever barked, but has begun to bark constantly whenever she is left alone... I'm told non stop for hours. When left at a friend's place, with another dog present, she kept barking so much neighbours complained. Otherwise she appears to be her normal exuberant, lovable self! I'm wondering if anyone has had a similar experience with an older dog suddenly barking like this & appreciate advice on strategies.