On the subject of Maine Coons...I had a mixed breed random domestic longhair who was a huge boy. Like...25 pounds and not overweight. But he never had any issues with his hips or joints and I'm guessing it's because he was a 'mutt' or something.

I had so many people who would come running to look at him and ask if he was a Maine Coon. I never said yes because his parents were regular sized house cats and I have no idea how he got so huge but I suspect it might've been a Clifford the dog situation. I loved him so much he got B I G.