What is wrong with duck's foot?

[maritimeducks]

Three days ago on bottom of duck's foot it looked like there was bumblefoot starting (two very tiny dots). I gave the duck an Epsom salt bath.

Yesterday she started limping but I didn't notice anything different on her feet.

Today I found these big squishy bumps on the web of her foot. Is this bumblefoot or something different?

 

[CherishedFowlGuardian]

What do the duck's feet feel like?
Are the bumps filled with something?

 

[maritimeducks]

What do the duck's feet feel like?
Are the bumps filled with something?

I lightly touched the bumps when I applied some antibiotic on them and they felt a bit squishy. I don't know if that means they are filled with something. She also has been limping.