Yes, the dose would be the same. The important thing is the % of medication and the expiration date, make sure it will be good as long as you think that bottle would last. I've never gotten a bigger bottle than the middle picture you posted. That will do at least a treatment cycle, and give you time to get more if needed, unless you have a really large number of birds. Once birds are exposed, and recover, they should be resistant to whatever strain(s) they are exposed to and not get sick again unless they are weakened by something else. Chicks and new birds brought in are at greatest risk. If you expose chicks to your soil from day one so they are naturally exposed to all the microbes there, it gives them a chance to build immunity without becoming sick. If raised by a broody hen that happens naturally, if in a brooder provide them with a saucer of soil from your yard and change it daily. That way when moved outside they are not suddenly exposed to things their bodies have never seen before. I still keep the meds on hand just in case, but have not had an outbreak in about 6 years.