Exactly!I want to add one more important thing: With most chicken diseases (if not all) there is not one clear-cut answer as how to treat them. One example is de-worming. Some people routinely de-worm their chickens every few months. Others say that you should never de-worm them, because that messes up their natural resistance to worms (or something along those lines). Another example: Some people swear by diatomaceous earth and put it in their coop routinely, others say it will harm the chickens and should be avoided at all costs.
Keep in mind who is giving you advice (a random stranger on the internet, like me, or a trained vet?), study yourself, and use common sense.