How do I know if my chicken is fat? I have an Orpington who is VERY fluffy and petite but I worry about her weight. She is the only one of my chickens that has a full feeling breast area. I can feel the Keel bone just fine. The other chickens have a bit of a protruding Keel bone and fairly skinny breast area. They've been checked for worms and are fine, just young and skinny. I do not see her at the food bowl excessively. They eat organic layer crumble free feed and occasionally get a little lettuce, watermelon etc... She's like a little puff ball and is the sweetest thing ever. Lol I'm hoping that it's an Orpington thing maybe.