I have a less than one year old Cochin. She had started to... cough? It was like she was gagging and trying to cough/puke something out by force. She stretched her neck out as she shook her head and made a drawn out coughing sound (lasted about 1-2 seconds). Her eyes also were a bit puffy and bubbly, but clear bubbles and only a few. I separated her and started treatment with 2/3cc tylan 50 orally and tylan soluble in her water. After the first day she was coughing normally, if you understand my meaning. (It wasn't so dramatic or drawn out.) She also had a phlegmy sound to her when she coughed at this point. Past day 2, no improvement. She did have less puffy eyes and no bubbles. It is now day 13. She never stopped eating, drinking, or pooping normal. All this time, no others have shown any symptoms. What could this be? She did respond to the antibiotics, but... what can I do?