I am concerned about the man's pets. He should not have any because he abuses them. I'm sure that doesn't help your mental health either to watch this happen. Please let his family know what's happening and that if nothing is done, you're going to call your local Humane Society or ASPCA to deal with the problem. It doesn't matter that he has dementia, it's not OK to beat and kick helpless animals.

Meanwhile, remember to take care of yourself and tend to your own needs. You cannot pour from an empty vessel.