Yes that is good stuff too. I have to order online most everything I need for my flock, here is a good place to buy meds https://allbirdproducts.com/products/baytril-10 There are other places too.
And Ebay carries some things too. Maybe Amazon I don't use them.
Can you take him home? He needs to become a pet again.
Terramycin is the best for clearing up an infection. Sometime foamy eye can mean they aren't cleaning their eyes out with water like ducking their heads. Which Muscovy aren't as water crazy as other domestic ducks are. Veterycin would be...