I gelded the horse in my Avatar, a beautiful blanket Appy to boot, because the test for Dwarfism failed to materialise (I had waited four years) and his grandsire is a dwarf. His sire has thrown no dwarfs, his dam has no dwarfs in her pedigree, but as a stallion he could, in theory, have sired up to fifty potential carriers a year (OK, so few of us actually breed this many, I am talking theory) and I was just not willing to take the chance. He shows NO signs whatsoever (he is a show horse) his sire shows NO signs whatsoever (also a show horse) but it is, potentially, in there.
The thing that annoys me the most about dwarfism (after we have overcome the helplessness and the heartbreak) is that I am pretty sure if a few more people with some serious money could throw some of it into the research it could be sorted. Then, of course, we would have to actually get the registries to insist on mandatory testing and eventual removal form the gene pool.
What do we actually have?
People who say it's OK to breed the pair again, just not to one another!!!!
We had a similar situation with Von Willebrands in Dobes, and testing was, thank goodness, found almost immediately. That did not stop people ignoring the problem for a bit. It was also said that if we were to act on the testing we would have no gene pool left but you know what? That was over 25 years ago and the Dobe is still here, and most, if not all reputable breeders insist on their sire and dam being tested, and the resultant pups being tested before being cleared to breed (not sure if your KC allows you to withold breeding status, ours does) the KC did NOTHING!
I think we can forget our registries doing much, too.
If we breed, we have the responsibility to say when this happens, and not be ashamed of it. The support people get when somehting like this happens , on this Forum, warms my heart, it really does.