It is a common problem in several dog breeds. Mostly smaller breeds. Years ago I purchased a dog. He cost me over $3,000, which in those days was a heck of a lot of money. I showed him to his championship, which I do with most of my dogs before breeding. This was in the days before genetic testing came about. As he grew older, I discovered he had a patella problem and was also obviously in pain. In his first and only litter, there were two girls and three boys. I had kept two boys and immediately neutered them. One boy went to a friend of mine who trained dogs for the movies. He was also neutered. Both girls went to friends who spayed them, since they were not to be used for breeding. I had to neuter my beautiful show dog. Killed me to have to do it.
I did inform his breeder, but she didn't want to hear about it. Sadly, all these years later, she is still breeding this same line of dogs.
Unfortunately, when dealing with animals, things don't always work out as one would like. We have to bite the bullet and deal with it responsibly, or breed from animals with problems and say nothing.