Shadera, RobNJ, thank you both for your thoughts!

I have experienced this in cat showing. People are very picky about letting others pet or hold the cats, due to possible transmission of diseases. I think if proper QT rules after a show are followed, and the animals that are being sold and shown at the event are watched over carefully and handled as little as possible, by as few people as possible, it will reduce the risk to a negligible amount.