I am losing chickens to what appears to be a respiratory disease. The birds are coughing sneezing and the eyes are crusty and appear to be bubbling and swollen. I have a mixed flock and as of rite now the only birds with any symptoms or deaths is a group of easter egger silkie crosses I hatched out 4 months ago. This has been going on for several days and so far I have injected all birds with liquimyacin and provided water with vitamins and electrolytes. Anybody have a guess as to what Im up against and what else I can do.