I just checked my chickens today for bumblefoot. I haven't in a long time, and 3 of my chickens have a black scab on at least one of their feet. There is very little swelling. And they are not limping. Should I do something or will they heal up on their own? Also, two of my chickens I am going to cull in the beginning of september so should I try to do anything to treat their bumblefoot? Thanks!