We have a cat who was once just like this. He belonged to my grandmother and aunt. When my grandmother passed, Jin was alone for long periods of time because my aunt traveled a lot. My parents lived in an in law suite downstairs and and would feed him, but he was scary so they mostly left him alone. He became flat out nasty, inflicting terrible wounds on both my mom and aunt. They were going to have him put down because he was unpredictable and dangerous. I knew he was just terribly lonely. Loneliness does terrible things to both people and animals. I wanted to give him a shot.
We talked them into sending him to us. I work from home, so spent a lot of time with him. He also had other cats and dogs to be around. When he got aggressive, I put him in room by himself. Eventually, he seemed to realize that he’d get a lot more attention when he wasn’t nasty. It took about 6 months of consistent behavior modification to “fix” him. I think we were lucky since I could be home with him, but my aunt thinks I’m a cat whisperer. We’ve had him for 10 years now with no other behavioral issues.
But, neither my son or his wife are likely to listen to anything I suggest, unfortunately.
