IvysAnimals
Songster
I used swimming to help them build strength and it works great! Glad you brought that up!A wanted to add a couple more things. With ducks and legs, swim therapy is a great way to strengthen them. You will want to be careful depending on how well your duck can hold itself up. You may end up needing to wait till it is stronger and it may take a while before you see improvement with the naicin. But putting it in a deep bath where it can float and still kicks it's legs can be a great way to work them out and build strength in the legs with the stress off added weight. I would start slow with swim therapy, but it can help a lot.
Here is also some information on tube feeding. I wouldn't usually recommend it if they are eating, but I would definitely get the supplies and have them on hand. The supplies are not always the easiest to find and when you need them, you often need them quickly.
https://www.backyardchickens.com/th...ng-guide-pictures-under-construction.1064392/
The one reason I bring up tube feeding is, in my personal experience, I had a Pekin duck with a leg injury at like 5 weeks old. She ate a bit of food, but not enough. She eventually had a hard time holding her head up. We were unable to get supplies for tube feeding and lost her. So while your duck is eating, if it is not enough, it could need require this. If you do need to tube feed while your duck is eating, you should only likely need to do it as often with ducks who are not eating at all.
I am also going to tag @Miss Lydia on this, because she is also a great resource for issues like this.