There does not seem to be unanimous agreement among experts for what is the ideal age to breed a dog, but a lot of experts seem to think it’s best to wait until the female’s second estrus cycle (heat). Generally this will probably be around ten to fourteen months, depending on the breed.
It’s important not to wait too long as a female dog’s pelvic cartilage hardens as the dog ages. Other tips include breeding a virgin bitch with a more experienced male, using an inexperienced stud male with a bitch who is not a virgin, and taking the bitch to the stud’s home.