I have a chicken with what seems like a cold, she is not eating or drinking and has her mouth open most of the time, there is some mucusy stuff coming from her mouth and you can hear gurgling in her breathing, sunken eyes, swollen sinuses so I separated her and put her in a box overnight ( much warmer than in the coop ) tried to get some water into her, next day I dissolved a triple strength garlic horseradish and vit c tab in water added some chook vit drops and a probiotic powder to the water and eye dropped it into her mouth got some down. gave a second drink during the day and again inside in the box overnight, gave her more water mix and some mushed up food. she seems to be responding to the garlic ect, not as noisy breathing and did try to eat a little herself but i gave her more and rubbed a bit of Vicks under her armpit and a dab on her nose will see how she is tomorrow, any other suggestions appreciated. all a learning curve