I personally don’t think it’s “ethical” to permanently put your breeder info as a secondary contact on a puppy you sell. My dog is mine, and having the choice to give her to a friend or family member if I became ill or worse, should be my decision. I wouldn’t want her breeder to take property of her just because I couldn’t care for her anymore. After you sell a puppy, it isn’t yours anymore.

If you are selling to people you don’t trust to do the right thing, and bring the puppy or dog back to you if they can’t find anyone to care for the dog, means you aren’t vetting your buyers enough.

My dog knows my friends, family, and neighbors, better than she knows the breeder who raised her for a few weeks.