Do the same instructions apply for a duck's foot? Unfortunately, I don't see a black scab. Does that mean it isn't bumblefoot? It is swollen & there is a lumpy area...I will try to get a picture uploaded! Is there a mobile version of this site?
I'm not familiar with ducks, but I would imagine it would be the same. A picture would really help. There usually is some type of scab, large or small involved with bumblefoot.