I have a 13 week old Silkie that has a lot of chest congestion. She started off on Friday looking listless. When we picked her up, we noticed she had some chest congestion. We immdiately removed her from the flock and on the advice of a friend with years of experience, started her and the rest of the flock on a tetracycline powder that gets mixed in the water. I wish I remembered the name, but I left it out in the barn. We have been giving it to her through an eye dropper. She seems to be getting more congested although a bit more animated. I am not sure we are doing the right thing. No one else seems to be congested or lethargic. Should I call a vet?