It's possible, if your father meets the legal definition of someone no longer capable of managing his own affairs, which is the primary requirement for a court to put someone under guardianship.  Your father's age is a good start on that, and the fact that he is enduring these conditions without an effective resistance on his part will help, and the worse the details of the situation can be made to look (for example, if your father turns out to have multiple flea bites, or other specific consequences of deadbeat's neglect), the better your case.  You need a lawyer for this.

yes.  Your father must be evaluated by a psychologist or phsychiatrist and the diagnosis of the doctor must be supplied to the court with the petition.  I may be able to assist you.  Please call me at John R. Tatone 586-868-5100