I have a very small flock, 7 guineas and 3 chickens. One of the chickens has had a sneeze since I got her about 2 months ago, she also has a slight rattle to her breathing that sounds like chest congestion and occasionally has almost diarrhea like poop. Other than these symptoms, she seems perfectly healthy. She free ranges around the yard with one of the other chickens, will follow us around the yard waiting for us to kick up or pick up bugs for her (she loves to be hand fed!), generally has a very healthy appetite. The other two chickens seem healthy also, as do most of the guineas. One of the guineas has developed a sneeze this week. Does anyone have any ideas about what these symptoms are symptomatic of? I've been having a really hard time narrowing it down since the sneezing chicken seems to be healthy and happy other than the sneeze and possible chest congestion. I started giving them Poultry Nutri-Drench mixed in with their water hoping the vitamins and everything would help boost their immune systems so they could fight off whatever this is. I'm starting to wonder if it could be something that I could/should be treating with an antibiotic, or what it would hurt to treat with an antibiotic. All the birds are about 4 months old, none of them have started laying yet. Thanks for whatever suugestions anyone might have!