I can do it if everthing is all ready before. But helpers are always good, especially if you have to wrangle the chickens. After dark on the roost is a good time to grab them, while wearing a red headlamp, but other times are a pain. It would be easier to treat only sick birds. If you can find a vet who will give you Tylan Soluble Powder, you can mix 1 tsp into a gallon of water for 5 days. Sick birds may not drink well, and must be encouraged to drink.