I see your point, Jimmy
Birds are not over-crowded. They have ACV twice a week. Small slice of garlic cloves twice a week(tedious he he he). Plenty of exercise and sunshine daily. I use SuperVit or Belgabion as vit supplements. Ideal pill once a week or as needed. Lofts and cages are cleaned daily. Drinking water replaced twice a day.
Subject bird eats well. He exercises with the bunch, but of course, seems short of breath when he lands.
He is now "isolated" in his own cage but I let him out daily to exercise and get sunshine. I went ahead with the Doxy + Tylan today. I thought it was worth the "risk". If the medication affects his moult, so be it. After all, I have no plans of racing him. He has become the "loft pet" LOL. He lands on my head most of the time. So, "culling" is out of the question
I think I made a "sound" decision in treating him today. His condition needs the necessary treatment.
Again, many thanks for your advice and insight.
Regards.