I read that in Merle's door but there is so much backmassing that I wonder if it really makes that big a difference?
My longest lived GSD (15) was heavily linebred on Lance of Fran Jo. My most recent 3 dogs are all outcrosses for 5-6 generations. Two died of cancer by age 9.
What is the difference between outcrossing and backmassing? - Akron German Shepherd | Examiner.com