I have a duck who is 10 years old. And surprisingly she is still laying eggs once a week. Today she layed an egg that was MASSIVE! it also had extra calcium build up on the shell plus it was misshapen. I have been growing increasenly worried about her becoming egg bound because of the eggs coming out misshappen and her being so old. She's a pet and I got her when I was a kid. Is there anything I can do to make sure she doesn't become egg bound or even something I can do to prevent her from laying all together?