I have a 5 month old calf that is mopeing around coughing. She looks great, not dehyhydrated and doesn't have the scours. She isn't eating much and isn't sucking on the cow. Her only symptoms are coughing, runny nose and she is breathing heavy...what could be the problem? I have her a shot of penicillin. the only thing i can think of is the weather we have been having. We had several nights that were very cool and rainy and now its HOT again?? Would that have anything to do with it?