roo making a gurgling noise

[rookflock]

My Rooster a Lavander Orpington started making a gurgling, raspy kind of noise and stopped crowing maybe a week or so ago. Also noticed his waddles and cone were dark in color. I administered Aueromycin for 7 days, his waddles and cone are back to red with just a little dark tip but he is still gurgling a little. Anyone have any ideas that may help. We had also gave them some tomatoes and grapes, if that is revelant. Thanks