I have a drake who's recently gotten ill. His symptoms are lethargy, lack of coordination, watery poop, discharge around the eye. He's stopped eating. There was a white substance around his vent. He also seems to have trouble swallowing, and his breathing is harsh. I know these are worrying symptoms. I've looked up several possibilities, such as duck disease or vitamin A deficiency, but his symptoms don't match perfectly and I'm wondering if anyone has heard of an illness with these specific symptoms and possible treatments. He is 1 yr old now and lives with another drake and a female. Any help is appreciated.