I have had some chickens, all were heavier breeds, that ended up with bumble foot. One girl actually plucked out her own bumble foot "kernel" while at the Vets. She was a Bielefelder who was towards the end of her laying years - putting out XXL eggs (105g). That was a few years ago when Bielefelders were legit and not from the now tainted Greenfire lines, directly/indirectly. Anyhow, it pains me to see chickens suffer with this disease. I had come to learn that roost height can be part of the problem, and that chickens jumping down (especially heavy chickens) from taller heights, are more likely to get this disease. SO, after a little more research, I realized this is an EASY fix: lower the roost heights! I literally have a roost that is just as tall as a cinderblock. I placed a cinderblock on each end with a board between them. The chickens do just fine on it. The highest roost I have IS less than 2ft off the ground, BUT there is a bale of straw below it, so they do not HAVE to jump straight to the ground from the roost. I've not had any issues with bumble foot since I've lowered the roosts. Although some chickens would like to roost as high as one's house, it is not necessary to their health to create high roosts. and can even hinder their health. Just an FYI that many here may already know 
