Crop problems as well as respiratory infections or diseases can cause rattly breathing. Check the crop to see if it is full and puffy or hard, then again early in morning before she has eaten or drunk fluids. A respiratory disease can cause watery or foamy eyes, swelling around an eye, nasal drainage, wheezing, sneeze or cough, or gasping. They may have only one or more of those symptoms. Depending on symptoms, a virus is usally not treated with antiobiotics unless they are very sick, but bacterial diseases can be treated with Tylan 50 injectable.