My five week old duckling goes through periods of time lasting about a half hour or so where he/she smacks his lips as if having an issue with swallowing saliva. Also there is occasional hoarseness and then more smacking of the lips. Once in a while there is what sounds like a cough, then hoarseness. After drinking water the hoarseness goes away. Any ideas? I thought if I was lucky perhaps this is part of the vocal change or something, but I don't know. Otherwise, the duckling is healthy, alert, no nasal discharge, no raspy breathing, no listlessness, etc. Please comment. Thanks.