Lameness in Pekin ducks

[DuckNana207]

Hi all! We have had several bouts of lameness go through our Pekin ducks. It started with one a while back, then a second, and now my husband noticed a third this morning. The first 2 have had a swollen digit (toe) that has spread to the ankle. I haven't checked the third yet. The first 2 I was able to remove a mass in the foot (bumblefoot?). The first duck all swelling had gone down, and then I removed the mass. The second still has inflammation, but I was able to remove a mass. What could be the culprit? They have a ramp to their house, but it's not as wide as the door, and they choose to jump up inside instead of using the ramp. We have trouble keeping the pen dry by their water. We have a rough portion of lawn due to landscaping (they are free range).
Also, any advice on how to get weight back on a duck and encourage eating? Our first lame duck (Chuck, who is female ) is no longer limping, but is underweight and weak.
Pics are of the feet after mass was removed, and the "stuff" I removed.

 

[JacinLarkwell]

Is there anything they can puncture themselves on? They might be poking their feet on something and getting infected

 

[DuckNana207]

Is there anything they can puncture themselves on? They might be poking their feet on something and getting infected

There are rocks and roots in the rough part of the yard... I'm kind of thinking that's our problem, because they were fine through the winter. I found a scrape by ones toenail, and the other had a "spot" on the front by her nail.

 

[Isaac 0]

Hi, there!

Just checking in to see how your bird is doing. Updates to these type of threads are quite useful for people in the future experiencing the same problem.