I have taken in a two week old duckling. One of its legs is deformed and twists backwards . It can drag itself but can't walk. I have known this duckling from the start and it seems to be a birth defect rather than a previous break. I would love any suggestions and will try what I can for it. It is thriving in every other way. I will try and attach a photo to show its bad leg. Thanks!
The photo would help, but I've heard of and seen this before, it is indeed usually a genetic defect obvious from hatching onwards. One duckling I read about had his foot amputated and a prosthetic attached instead, but others have had corrective splinting, surgery, etc, but the latter in particular must be done while the bird is quite young and 'plastic'. Best wishes with that issue, whatever your choices.
Good that you took this little one in! If he or she is otherwise healthy, I think it would be worth working with the duckling and providing as content and safe a duckie life as you can. There may be some ideas here that will help you https://sites.google.com/a/poultrypedia.com/poultrypedia/poultry-podiatry A combination of braces, prosthetics and nutritional supplements is how I would go forward with this. You may be able to find a vet willing to help out. And there are crowd funding sites where people raise money for all sorts of projects.