[Abby]

First you ask your breeder, I think the best question to ask is whether there's any possible health problems to look into in the pedigree. When a breeder combines two dogs, there's never going to be a perfect combination- hopefully they're avoiding the most dangerous problems, this could mean they're taking a chance with two pedigrees that might produce, I don't know, allergies, or vWD, if they truly believe the puppies will have great hearts. If you ask about health problems in a puppies pedigree and they say "Our dogs are the healthiest on the planet, there are NO health problems in this pedigree!" or anything about the entire pedigree being in perfect health- RUN. A pedigree like that doesn't exist, and an ethical breeder will be straightforward about it.

For most pedigrees you'll see only a few different kennel names that make up the majority. After asking the breeder of the puppy, I would go back and contact the breeders who make up the pedigree- you don't need to contact the owner of every dog, they'll probably know about most of them. See what they say and use that to help your decision.

We also have a few people on this forum who know a lot about working lines, if you sent them a PM and said "I'm researching the health and longevity in this pedigree, and if you know anything about these dogs it would really mean a lot to me" they'd probably be happy to tell you what they know.

Good luck!