I find this thread very interesting. My flock got bumblefoot for the first time last year but not all of them and they were all one breed, Golden Laced Wyandotte (I have similar size birds, Dominiques, who did not get it. One thing I did notice was that the Dominiques used the feed bins as an intermediate step before landing on the ground from their 5' high roosts. The Wyandotte did not). Out of a dozen birds, only the roo and three hens got it, the roo was the worst. I performed the surgery to remove the "kernels" and they all healed up nicely. It's not a fun thing to do but they were very good about it. Antiseptic, neosporin, gauze, vet tape, and a week in a separate, very clean pen before returning to the flock did the trick.