Sore on foot

[Apachefarm]

I noticed once of my gals has a small sore on the bottom of each foot, is this normal? I checked all the rest & no one else had this on bottom of foot

 

[Wyorp Rock]

Looks like Bumblefoot.
One foot looks like it has already been worked on, did you remove the scab on that one?

 

[Apachefarm]

I cleaned her feet off with a tooth brush.