I got two pekin ducklings about 4 days ago and they are now about a week old. One was smaller then the other and much more tired, I took him back and they told me that je was just tired from his trip because he was only 2 days old. He was acting fine after a day and eating as much as the other but then he started sneezing...at forst it qas every so often and now it is all the time, he is now breathing with his mouth open and a clicking noise happens whenever he breathes. He doeant breath faster, but I'm lost in what to do. I bought him antibiotics but nothing has changed...I don't want him to die