Some(not all) of my birds I've noticed despite looking of normal size seem very lightweight. It feels as if they are feathers, skin, and bones. They are definitely eating well$$$$, The doldrums of winter are here so nobody is ranging three hundred yards away from home for the whole day; I'm just wondering why they're so skinny? Any ideas? Maybe I got spoiled by the cornish x's and got used to picking a chicken up that weighed ten pounds....
Max, have you checked for worms? Like you I was concerned about a few of my girls being underweight. I never saw any signs of worms other than the weight issue. We don't have a chicken vet around here. After discussing it with a few BYC'ers that I consider to be some really knowledgable people I decided to go ahead and worm. The girls that I had concerns about are now at a better weight.
(Don't know about worm medicines.) Are these mature chickens and what are you feeding them, Max? Steve
They will be a year old in March. I feed them 16% layer crumbles along with some sunflower seeds, corn, and various other treats. Most of the time they eat the crumbles.
Do you have a vet that you can take some fresh poop to. I have a friend who is a vet and if I take her some of the poop she will test it for me to rule in/out for anything.