Recently a pair of bantam Cochins was given to me. The rooster is in rough shape with missing feathers, some clear mucus in his eye, and inflamed feather shafts on his feet. He's also lethargic but seems to have a little more energy after I've kept him on a diet of baby chick food, yogurt, garlic, and nutriental yeast since I got him (4 days ago) I showed these pictures to someone who has had chickens longer than I and he said to cull him immediately; he has Marek's. I've looked up what I could find and it doesn't seem like the classic signs...can somebody please help me figure out what's going on with this guy? And possible treatment?