I have a young muscovy drake that I noticed had what looked like goop or swelling in the corner of one eye. So, I caught him and after all of the flapping and thrashing was contained, I could see frothy bubbles in the corner of his eye. He is acting normally otherwise, and eating fine...if this were a chicken, I would say it was CRD or some other sort of respiratory thing and I'd give a 5 to 7 day course of Tylan 50 to knock it out. But since it is a duck, and I've never had to deal with an illness in any of my ducks before, I wasn't sure if their symptoms/treatments would be the same. I did find an article posted by dlunicorn that has a listing of common duck illnesses, but none seem to match. Also, it mentioned using Tylan 200, not the Tylan 50 that I already have. I assume this would just mean using a higher dose of the Tylan 50? For a standard chicken that is 6 to 8 lbs I used 1.5 cc per day, either sub Q or IM. This muscovy is probably more like 12+ lbs, so would maybe 2cc or even 3cc split up into two doses per day for 5 to 7 days be about right? For now I have done nothing besides pen him up so that he is separate from the rest of the flock. Would appreciate any advice on what he might have and if and how I should treat!