Yes. I have a female that has been with another breeder on this site since September 2007. She was in QT for 60 days, and then was introduced to his male. We have completed that particular breeder loan agreement. We had planned to have her breed to another one of his males last season, but that didn't work out (the male we planned to breed her to was not quite ready), and we agreed he would keep her on to breed her this season.
We'll have our second breeder loan this season, with a new breeder loan contract written up.
I'm taking in a female in the next month from another friend, and she will be in QT for 60 days before I introduce the male to her.
Let me make this clear - I trust BOTH of these breeders and know their collections (they both in fact have stellar reputations here and on Fauna) and know that they keep them as well, if not better than my own. But I am STILL practicing QT. Our animals have been kept in different collections, exposed to different environments (with subtle differences) and have built up their own immunities to their own specific environments.
QT not only protects your OWN collection, but allows the new animal a chance to acclimate to a completely new environment.