Correct me if I am wrong but you do not get a fee for photographing these dogs and you send the proofs out with the hope that they will order. Seems like a win win for the exhibitor and nothing for the photographer.
So photographers send an image (their choice) and then send it with a bill.
Please tell me how this way of shooting ever got started. I do not know many people that work that hard, send out images and wait to get paid!