Waterfowl Foot Injury/Illness

[The Big Mo]

Friends, need some guidance... We have a flock of waterfowl with Toulouse, Sebastopol, Khaki Campbell and Pekin. Over the past couple of years our birds have suffered from foot damage/injury. I have included pics of what it looks like. It starts with a black dot on the webbing and continues to grow until the webbing is gone. We have used topicals, blukote and a few others. Once the black spot appears, almost if nothing effects it. This happens to ducks and geese with the end result the same.
Our flock is free-range (4 acre pond) and is supplemented by cracked corn daily.
Thanks for your input...

 

[SmiYa0126]

@Miss Lydia please help!

 

[Miss Lydia]

I wish I could help but I have no idea what this is.

Lets see if we can get @casportpony to look.
@The Big Mo
Question, once the webbing is gone what then do they lose the foot?Where does it end? I wonder if this isn't some kind of bacteria living in the pond like the flesh eating bacteria? Might be a good idea to have the pond water analyzed.It can be done we had our spring water analyzed when we move here.

 

[Barnette]

I would say some sort of fungal infection but I really don't know. Maybe put some ACV in the water and yogurt as a treat? It couldn't hurt to try