I have no tolerance for poor temperament,meaning aggression towards other dogs or people.

There are certain old lines or dogs known for that part of poor temperament.

As I see some talking about breeding to frozen semen from dogs they never saw or met, that didn't have the clearances done today, that not many knew the true temperament of these dogs, it would scare me to use some of these long time lines or kennels.

That's just some thoughts of mine breeding to these dogs from the past.