yes,, I've read that. But whatever. Oxytet works wonders for respiratory issues. Which, if you read further, you'll see that it's one medication that's been recommended. Tylan is way overused imo. Choose your poison. Denagard works for MG, also.. But in a case like the OP's, I'd start with Oxytet. Not everyone has the resources to use State vet testing, etc.We're talking about a small backyard flock, not a breeding or commercial operation. And since the OP chose to contact their vet perhaps that's the person to make the final determination.
Also, just because one person has a bad experience where they had worsening symptoms, it does not mean that every flock will have the same experience. It just depends on a lot of different factors.
It's true that it could be one of a few different things causing these symptoms.