So this little guy (or gal) wandered into my yard yesterday and made itself at home with my muscovies. I watched him run his beak along the ground attempting to eat and after not being able to pick any food up he'd lay down somewhere. He looked really dirty and rough and was getting nipped when trying to get close to the feed dish. When he tried to run away he'd fall and use his wings on the ground to get away. I caught him and noticed that his upper bill seemed to be trimmed and his lower one sticking out-- which to me would explain why he can't pick up food. He was also filthy, matted, and his feathers are just breaking off and falling out. I syringe fed him a mixture of wet cat food, starter/grower feed, nutri-drench, acv and water pureed and he ate from the syringe happily (although not so happy to be picked up and handled). He's much more active and alert today after several feedings but he still doesn't seem to be able to eat on his own, he just waits for me to come with the syringe. Can I trim his lower beak? I don't really know how to do this, I was thinking of trying to gently file it with a course nail file. I don't want to hurt him. He's feeling better so I'd be comfortable releasing him back outside if I only knew he could eat on his own. I'll attach pictures below. Suggestions?