Time to set some things straight.
First of all please stop complaining about what someone has done with YOUR “pet homed” dog. It is our responsibility as breeders to spay/neuter our stock accordingly. If you had taken care of that in a timely manner it wouldn’t be a problem.
Yes it’s great to wait until after 6 months but their are plenty of shelter and rescue dogs that have made just as great pets spayed/neutered between 8-12 weeks. If it’s done already when they leave no worries. Sometimes withholding paperwork is not enough. Another practice done with some responsible breeders is a money back option when you fix your pet after 6 months. People pay the full registration price and the difference is returned when they send proof of spay/neuter. Altered dogs can still be shown they do not have to be intact.
There is absolutely no reason to sell a dog eligible for registration without paperwork. Paperwork gives proof of breed which some people need in this BSL world. Permanent registration can be done marking the dog as altered do your research. Spend your money where it matters.
Second, there are safe guards you can put in to protect your stock from open single registration it is not UKC’s fault that you have failed to put them in place.
For example: DNA-Profiling allows you the ability to challenge any single registered dog claiming your stud/dam and have it’s papers pulled if they do not comply or if they results do not match.
Do NOT breed your stud to any female without seeing the proper documentation and cash in hand. If you choose to work pup back deals and it doesn’t work out in your favor you can’t be mad at the registry because you did something that didn’t work out. If your stud has multpile litters he should be DNA-Profiled anyway it’s in most registries book of Ethics.
Yes I could pull any shelter, rescue or stray off the street and single register it with UKC with either no pedigree or a made up one. They may or may not catch it. Doesn’t make it right but neither is hanging paperwork on Bulldog mixes !