Last two suppoedly sisters, at age 12 Belle, started doing strange things. Sitting and waving a paw ....for 10+ minutes at a time, sitting and staring into space and swallowing as if she was trying to swallow food, bumping into things like a chair or table legs or a wall Vet found nothing, minor cataracts. She started stumbling and fell a few times just walking across,the floor. We made the decision...broken hearted...she and her sister Kelle’ were very small, 14# , Kelle’ is now 13 and is starting to do odd,things also. When going out she will stand in the hinge side to f the slightly open door and must be guided out the open door. We know,she is nearly blind so bumping into thing is logical, she is starting to duck from our reaching out to her as if she had been beaten, any noise has her being startled and ducking. I am afraid she is goinG down,the same road as her sister, but she is,not in pain. So hugs and love are our direction at the moment. Yes i think they do get old age mental problems.