Not sure what you mean by cull harder. If you normally cull the substandard pups out of outcrossed litters . . what more can you do out of close, family matings? Kill em twice?
Whether it's an outcross or a brother X sister litter . . I keep as many of the pups as possible and I slowly whittle em down to kindling. I have an accidental brother X sister litter right now and I already have my eye on a couple as least desirable and a couple as most desirable. At this stage it's all appearance and personal preference issues. As they grow they'll fail or succeed based on personality and performance issues. But nowhere in this process will witchcraft or superstition play a role and my selection process is exactly the same regardless of the relationship of one parent to the other. I try to keep a good one and try not to keep a sorry one.
