Black mass on Duck feet

[Lenny loves chickens]

Hi, I have a duck with bumblefoot that I am currently treating and seems to be getting better. My issue is that one of my other ducks who I thought may also have bumblefoot has this thick black mass on her feet which is nothing like my other ducks feet. I’ve been soaking her feet in Epsom salt for 2 weeks now, spraying on some antibacterial solution and have used silver gel but I don’t know if I’m doing the right thing here? I feel so terrible for not picking up on either of their issues sooner. Can anyone help me please?

How old is the duck could be a callus...

 

[4Duckssofar]

How old is the duck could be a callus...

She’s 8 months old. The scab does come off in bits but it just seems to bleed. I really don’t want to be doing damage to her little foot.