I looked around for posts concerning similar issues, but couldn't really find any. These are my first ducks and they're 3.5 week old runners. I give plenty of niacin, ChikSave, bugs, veggies, ChickStarter with nutritional yeast, and water, but I still see nasal discharge and shaky legs. I clean the cage 2x/day and have no drainage issues in the brooder (an elevated dog kennel). Thanks for any advice you can give!