I have 2 ducklings. I'm a first timer duck owner. Had them almost a month. Seems to have a hard time breathing. Like heavy breathing. Also likes to be in the corner by himself like he's in trouble...most of the day. Nasal passages seem clear and are able to clear them. The quacking sounds like larangitis (sp?) while the other is loud and clear. Not as active in the pen as the other either but eats , drinks, and poos normal. What could be wrong with my poor duckling? Any ideas?