I have been offline the past few days and caring for the farm through the terrible weather. I just wanted to report back that the ducks all seem to be doing well. I moved them out of their pen and relocated them to another area in case there was something there making them ill. I did deworm all with ivomec as I had stated in the first post, I did read up on wormers as well. Thursday there was another case of coughing so I decided to give sulfamethazine antibiotic mixed in their water. I removed their pools as well so that they only water they had access to was the medicated. Today is day 5 and last dose of antibiotic (according to package). All ducks seem to be doing well and the coughing has stopped. I am not sure if it was worm related or respiratory issue but I am happy to see that everyone is on the mend. Thank you everyone for sharing your wisdom and experiences. I just wanted to post back and give an update.