My father has dementia (84). Lately, he doesn't want to get out of bed, mobility is getting slower and slower. What stage is this?

Looks like ur post got lost in the shuffle.

Incontinence usually comes about before the last stage. In my opinion, he needs to see a Dr. There can be all kinds of reasons why he seems weaker. Could be dehydration, low potassium levels, thyroid, diabetes, low blood pressure.

Would hurt to have some labs run.

There are certain causes of dementia so speaking with his doctor (if you're on his HIPPA form) to learn about his diagnosis would help. Incontinence can be caused by many things. he needs to be seen by a doctor ASAP. He could have any number of things going on such as dehydration, depression, infection, chemical imbalance or progression of disease process. PT at home may be ordered by the doctor to help him.