Though not my dogs, I care for the neighbor's two dogs because their owner is a self-centered moron without a clue regarding interaction with, or caring for animals. He bought them years ago so his lonely teenage son would have companions. When the son went overseas for college, I took over their care. One is a blond lab girl, and the other a combination of pit bull and German sheppard boy. The boy is the oldest, and has always been the dominant dog between them. Even though smaller, he was always faster, had the best eyesight, and was more agile and aggressive. Whenever they play fought, she would always fight from the ground laying on her back in a submissive posture. The last three years the boy has aged to the point where he's lost most of his hearing, and his legs are all but gone. His eyes are still good and his character hasn't changed. Just his mobility. For some reason the girl lab has now become abusive toward him. Most disturbing of late is that she'll take on a defensive posture (back hair raised) and stare him down to the point where he cowers and walks away. I've seen her snap at him as well. Perhaps this is what canines do with older dogs who can no longer fend for themselves - a pack mentality to rid them of any threat to their safety. Their way of saying, "It's either you or me that's going to be eaten by the lion, and it ain't gonna be me." So what I do to lower that tension between them is have the lab lay on the ground in front of him, with her belly up in the most submissive posture possible. Immediately his confidence returns and he'll amble over to be petted. I had to do this just this morning before our morning walk. For some reason she didn't want him to come along. Maybe it's the slowed pace she doesn't like when he joins. She prefers running. Anyone else with animal behavior observations?