I have a pretty large (I don' t know the breed) 2 year old Rooster. Sometime ago we noticed him limping. We also noticed another large 4-5 year old hen limping. I have two younger smaller birds (Aracauna and ISA Brown) that were having no problems. I decided that their brooding boxes were too high so I put a bale of high under it, and I lowered their perch. The hen seemed to get better. I thought the rooster got better, but then I saw him falling down. Then I watched him repeatedly jump on his perch and fall off. So I put a step behind it, but he stopped getting on his perch and just slept on the floor. I thought his leg got better but the other day it got worse. Yesterday he didn't leave the coop and today he can't walk at all. His legs are stiff out in front of him. I'm trying to put food and water in front of him where he can reach it. I'm pretty much a rookie here with just three hens and a rooster. I don't know what to do with him except to put food and water in front of him where he can reach it. The other hen seems to be fine. I had read about Marek's but it seems to be a disease of younger birds and very rare among older birds, or did I misunderstand.