Queenbee, if you are in the states, you can notify the local senior services in the county where they live and they will do an investigation of their living circumstances. At least they do in most states. If they are found to be in a state of neglect or in harms way then a guardian can be appointed and maybe they will have to be moved into a home or relatives will have to be notified - but it is dangerous to be in the situation how they are...

I am in a similar situation... my in-laws live in an apartment. My father in law wants to take care of his wife who has dementia and is blind and incontinent. He has tremors and in his poor health and I would say is starting to lose his congnitive faculities himself (he thinks 911 is new and does not know that area codes need to be dialed, for instance and is extremely hostile) but his son thinks he is fine and is living how they want. They only have help 5 hours a day, 6 days a week. The doctors wanted 24 hours a day 7 days a week. He makes very poor decisions and yet my husband will not intercede as his thinking is that this is what is making his father happy! So it may not be the doctor but the people making the decisions as the doctor cannot force the patient until damage has been done. Then the state can step in and actually take over.