You see, twice within just a few years we have witnessed an interesting phenomenon among our dogs and cats. When one of them becomes elderly, stiff and blind, one of the younger ones will step forward and care for them. The younger dog or cat will guide the elder to the food and water and generally stay close by, even sleep with him.
I think it is remarkable that animals on the lower end of the sentient scale seem to recognize the value in caring for their elderly. Why can't we?