Duck attacked, need some advice

Hi! So, something attacked my year old muscovy and I need some advice about what to do. I'm guessing it was a raccoon because his wings look chewed.. I've seen that sort of chewing on a pet pond turtle I had.. Anyway, both his wings are a little chewed up. Several of his flight feathers got pulled out and he's a little bloody, but not bleeding anymore. He definitely got bit on the head There's a cut covered over in clotted blood, so it's not bleeding anymore either. Could be a bite puncture, but it's hard to say. Doesn't look too bad. However, one side of his head/face is swollen! I'm guessing it's swollen from a bite. This only happened, like, 5 hours ago so I'm wondering if it could get that infected so quickly? He's scared, and walking a little slowly, but the rest of his body seems unhurt. I'm hesitant to catch him and put saline on him because it is 24* here and snowing a little. I don't want to get him all wet and cold. I would bring him in the garage, but he gets super stressed if separated from the flock. They have a nice, roomy, insulated house inside a really secure aviary. He's resting and, besides being scared, is acting pretty normally. I put them all in their aviary, actually, because now I'm worried about that raccoon! He must be sick or desperate because this happened in the daytime! Am I doing the right thing?