This is certainly an individual decision but please do not take sick fowl to a show and infect everyone else.
Amen to that!
If a bird recovers from a disease that has the potential to make it a carrier, I would cull, period. To me, there is no other option. I see folks on BYC all the time selling birds in BSA when they've recently had serious respiratory illness in their flock (which they've posted about), to me highly unethical unless they tell the buyer that the bird has the potential to make his/her current flock ill and then allow the buyer to make an informed decision. And you can bet that isn't something these sellers bring up to their buyers. Of course, that is a side issue to the original thread subject.
To reiterate, breeding for resistance does not mean you let birds become ill and recover and keep that bird in your flock. That doesn't make a resistant flock, only an immune-compromised one. It means you cull immediately (speaking only about contagious illness here).
Well, my question on this is .... wouldn't that be breeding for resistance? Say, for instance, the seller (in the BYC auctions) did have some illness and killed all the sick ones. Wouldn't the others be considered "resistant?" See, this is the part I don't understand.