Rooster with ear infection?

[friend of chickens]

Does anyone have any experience with a chicken that has an ear infection? My son is very observant and often checks the ears of the chickens. He told me that our beautiful copper marans roo's ears have yellowish exudate in his ears that is making the feathers on the outside of the ears stick together and it smells really bad. I have dewormed the chickens using Valbazen 7 days ago. I'm not sure that this would have any bearing on his plight. Please don't be offended that I'm not willing to take him to a vet as the chickens cost me too much already, but I am a nurse, and if anyone out there has any idea what this might be, or any experience themselves, I'd appreciate hearing from you. Thanks so much!