My kids started raising chicks through the 4H, and we’ve been keeping them for years now.
We’ve had a bout of intestinal issues that antibiotics or dewormers just couldn’t knock out. Then someone dumped a rooster in to our yard and he had severe scaly leg mites, which went through the whole flock.
Soooo... 2 drops white thyme essential oil into one gallon of water has worked WONDERS. I use NOW FOODS brand and I made sure it was their only water source. Now that the diarrhea has cleared up I’m just using 1 drop per gallon.
For the scaly leg mites: I took cheap vegetable oil and put it in to a tall plastic container, about a quart size. I mixed in 1 drop of the white thyme oil and stuck each leg into the oil up to the feather line and rubbed it in pretty well. I also tried it with 2 drops thyme oil on the really bad rooster legs and no one died. It’s been 2 weeks and the thick raised scales have fallen off and fresh new skin is emerging.
You can use thyme oil in water in a spray bottle in the coop too, esp on the perches.
Keep your coops clean!
I've got thyme planted near their run and they were surely pecking what they could. Good to know it's not bad for them.