My rooster has begun to give a bit weaker crow, as well as sounding "gurgly" when he inhales. I brought in some hens about a month ago, found out they were sick, and culled them. They did come in contact with my old flock for about 6 days. I have a bad feeling that they are all going to get sick and I will lose my whole flock. What should I do? I have 7 adult chickens, and 10 3-month chicks, which have not been in direct contact with my adults, but have been in their coop while the big guys free range.