Please forgive me if there is anyone totally against what I am about to say
I have Maddy she is 11 months old, as I have no idea where to start with regard to the whole breeding thing, we have had her speyed likewise we had our chocolate lab's jewels (I like that expresson) removed.
Choccy never missed his "jewels" and never bothered with any ladies he was nearly 12 when we lost him, I am having to watch everything Maddy eats as she has gained weight since she was done but we will keep on top of that for her sake.
I think what I want to say really is, if your dog is purely a pet then I think removing "jewels" etc is best for the dog and for you, we were told especially in bitches it can prevent mamory problems later on.
It would save a lot of bad breeding too.