I have a 6 months old Isa brown hen. I didn't notice anything yesterday, but now it sounds like there is phlegm in her lungs, almost sounds like a cat purring. The rest of the flock are healthy and active. Should I isolate her? The weather in Melbourne now is moderate, but the nights get down to about 10degrees C or 50F. I was thinking of bringing her inside and giving ger some garlic oil (Garlic oil worked like magic on another hens cat scratched pussy infected eye!)