Mom's dementia is worsening and she is starting to change how she treats her dog. Personally, I would love to just walk in there and remove him against her will, but I know that's impossible and would be borderline cruel to both of them. I don't want to wait until he's completely ruined. He is over fed and had gained almost 30 pounds this past year. He should weigh 80 pounds, and weighed 107 yesterday. He had a double ear infection and sores from allergies to the junk food she feeds him. She refuses to feed him dog food. It took me two months to convince her to let me take him to the vet. Now she's resistant to me giving him his medicine. She said she'll do it. She can't and won't take her own meds. How do I know when to do something, and how do I do it? She loves him, but treats him terrible at times, yelling at him and only letting him outside long enough to relieve himself. She never lets him get any exercise. The vet voiced concerned about the obesity, but when I told her about Mom's condition she couldn't really offer any advise on what to do, just apologies for what I was going through.
While it may be hard, you can call an ambulance for her the next time she is acting out of sorts, that way you won't have to get her in the car. Once in a hospital they can give her a workup and she can see a neurologist, who hopefully will get her the care she needs and give you the power to make the right decisions.
It sure is a terrible circle you are in.