Breeding for longevity
How does a breeder select for longevity?
I ask because a bitch is of prime breeding age from 2 to 8 (or so). This is well before a breeder knows if the dog will live to an advanced age and how well she will age.
With studs, the dogs can be bred a bit later, but in general, one is not breeding a 16 year old stud dog either, and it might even be ill-advised for puppy health- not to mention the stud's health.
I realize you can look back at pedigrees and see how long dogs lived, and talk to breeders to see how well they aged, but unless a breeder has been at it for a long time, and selecting for longevity, this seems difficult. Also, a few generations back the age of death is often not recorded and how well the dog aged is difficult to determine, unless the dog was titled at 10 years old or competing actively into advanced age. This is not usually the case.
I've also seen breeders claim that the less inbreeding, the healthier the stock (as espoused in Merle's door).
Breeders who select for longevity- how do you go about this?
Does selecting for longevity ever interfere with selecting for working ability, appearance, or temperament?