My Runner had almost the same thing I took her to the vet because I wasn’t sure if it was bumble foot since it didn’t look like any bumble foot I had seen. She was on the antibiotic for a week along with mextacam for pain an inflammation. I then took a scalpel and open it up from the top and mashed till the core pus popped out. I then sprayed Veterycin on it wrapped in in vet wrap and left it for a couple days thinking I might have to get more pus out but it had already started to heal and swelling was already going down. It took about a week for the swelling to go down all the way. And pus in ducks isn’t runny it’s thick and cheesy looking. Any chance you can take your duck to the vet?
That's exactly what it looks like in my little girl. Sadly I've been calling around today and can't seem to find a vet in my area that will deal with ducks. Not sure how to help her.
I had to go to the next county to take
Mine to one. I didn’t think the meds had helped at all at first but I do think the antibiotic helped to bring it to the surface. You can order fish meds on line which are same as what we and our feathered pets can take. Amoxicillin is what my Runner was on @casportpony can help with dosage.