If it is an upper respiratory infection, sinus infection, or ear infection, sometimes they clear these themselves in few days. I've had some even sneezing and sounding raspy. I put Nutra Cell in their water and Vet RX under their wings and near nostrils. Vet RX cures nothing, it's just a chicken version of Vicks so might make them feel better. Vitamins help them build immunities and fight whatever they have, like we do when we're sick.
Oregano is said to be a natural antibiotic, but I would stay away from essential oils of it because it is so potent, you could harm the chicken worse than helping.
Here is an
article about oregano from our BYC Project Manager.
I would try what you'd like to that's natural, but if no improvement in a couple of days, or she gets worse, she'll need an antibiotic.
