I wanted to get some advice. I started with 4 hens (buff orpington, barred rock, golden comet and an easter egger) one month ago. I decided to add two more yesterday. The same local breeder that I purchased the original 4 from had two that were the same age as the others so I thought it would be perfect. I brought them home and added them to the flock and the original 4 immediately began to peck at the two new blue wyandottes. They were in the same run for a couple of hours and I then created a plywood divider so the new birds could be left alone. As the day went on I noticed that one of the new birds had yellow discharge from her nostrils and had raspy breathing. This indicated to me that she has a respiratory disease. Kind of frustrating since I just bought her! I now have the two new birds on 1/2 tsp of duramycin 10 per 1 qt of water. Is it worth keeping the new birds as I heard they are carries of this disease for life? This was a foolish mistake as I now see that I should have waited one month to introduce. Also, should I treat the other 4 with Duramycin as a precaution? Below is a pic so you can see how they are separated. The new hens are on the left hand end of the run. Any suggestions or advice would be warmly welcomed. Thanks so much!