My parents have each other still thank goodness, both in their 80s my father is older and coming up for 90 and I am sure that is what keeps them going on but I know there is going to come a time that possibly one of them will need care. The thought of either one of them ending their days in a place 'not fit for a dog' frightens me hearing the stories that you do. How are you going to know for sure, because it appears alright doesn't mean that everything in the home is going to be ok. Despite their physical ailments that go with age they are both quite alert and still have very strong points of view about things. But if either remaining parent was to be left in a vulnerable position I would hate them to lose that spirit.