I was given 2 ducks, and one of them had an odd 'action' going on in its chest... it was like it's heart was trying to jump out, especially when it got anxious - I thought it was a birth defect of some sort... it ate fine, swam in the pond and was just an "odd duck". But this has developed into something worse, the poor thing seems to have a hard time breathing, and opens and closes its mouth like it would like to be quacking, but it can't quack. It isn't growing, and is definately getting weak. It does eat a little, but won't swim anymore, and doesn't even move when you go to pick it up. Should I try to find a vet... or is this a defective duck that probably wouldn't ever get well?