I know of a breeder who has inbred his bulldogs dogs 6 generations with no out crosses and his dogs are all said to be normal and healthy I have questioned him to death on how he has performed this feat and his goal was to produce a "blank dog" his stock has insane working drive and he reproduces clones pretty much every time he has a litter only the coat color on his dogs get lighter and the litter size remain small 4-6, and when he does outcross he goes back to chilled semen of his foundation dog for a natural out cross. He has a degree in animal science and has never had issues with cleff palates or other common symptoms, he does cull very hard. I like the fact that he breeds for performance and started his program by throwing away pedigrees and breeding based off instinct not what was said to be behind the animals. His breeding program goes alot deeper than what I have brought to light but to go 6 gen and have the same ped is a feat that isnt common! Ish Iron Guard K9