Droopy Pekin Drake

[PekinPrincess03]

I have two pekin drakes and yesterday one of them started acting droopy and kind of on cloud nine. He looks like he has lost weight. His eyes seem off. He isn't doing what he normally does. I let them out of their pen everyday to run around and he normally loves it but he will not come out.The other drake is fine and acting fine. The sick drake is still drinking well but I haven't seen him eat much. The healthy drake does beat on him alot so I am wondering if he is just lame. I don't have a vet around me that see's ducks. I am hoping someone can help. Do males go through molting because he does seem to be losing alot of feathers.