Hi, @CyndiD
Since I worry sometimes - I hope she cannot drink the Epsom salt bath? It's a laxative, she needs to either be held or maybe a compress around the leg instead (and oh, I comprehend how for some ducks this is not a good idea . . . Vier will hurt herself flailing around if I am not very careful how I hold her).
Okay.
Swollen, hot, if you can get to a good duck vet that would be best, ideally . At the same time, vets are not always a possibility.
So - it could be an infection, it could be something like arthritis. So an anti-inflammatory is needed. There are natural anti-inflammatories, both topical and oral. Turmeric is something I have started to suggest after clearing it with my vet. I do not know if there has been much research on this, so I cannot suggest a science-based dosage amount. I was told it would be difficult to give too much (but stil....). And please forgive me for shouting, but if someone in the future reads this post quickly, I don't want them to miss this: TURMERIC STAINS - YELLOW TO BROWN DEPENDING ON WHAT YOU'RE WEARING. IT STAINS SKIN, TOO. But it is known to be anti-inflammatory.
Topically, there are some homeopathic and herbal ointments. I like comfrey, that I make at home, and T-Relief that I can buy at the drugstore (call ahead, sometimes you have to look in the health food store).
If it's an infection, then something to deal with that is needed. I would be tempted to try clear iodine topically. My reasoning (remember I am not a vet, nor a vet tech, just a duck lover) is that based on how I have seen it work on bumblefoot, I think it sinks into the skin a little bit. Another "at the same time" thought is that it might be better to treat with something that gets into the bloodstream to prevent the spread of infection and really get into where the joint is.
Oregano is used by a number of poultry farms to "reduce the need for antibiotics," and I have read it has antimicrobial properties.
Feed stores sell antibiotics, as I think you know . . . and I often rely on @casportpony
and some of her posts. @Orca5094
has also been helpful, as has @Lacrystol
. And many others, actually - so if any of you with more antibiotic experience could make some suggestions here that would be kind.