Frequency of Breeding
Ideally, a bitch should only be bred every other year and she should not be bred much before two years of age. The season closest to the second birthday is a good one to start with; certainly no earlier than this. In some breeds, you may need to wait one more season before beginning. By this time, she is better prepared mentally for having puppies than she would have been with her first few seasons. Her physical growth is complete and pregnancy at this point won't endanger her health, provided that she is healthy to begin with.
It's important, however, to keep the frequency of breeding low. Even at maximum, you want to allow at least one unbred season between breedings. This allows your bitch to rest and regain her strength. A bitch that whelps too often will produce weaker puppies more likely to die, and the repeated pregnancies are pretty rough on her, too.
http://www.k9web.com/dog-faqs/breedi...i_breed_my_dog
Here are some facts written by an author that did research about breeding dogs and being on the "safe side"....thats the best decision when breeding is how can this be done for the best interest of the breed and the dog...not lets step out of the box whether its ethical or not and then try and find someone, ANYONE, to support what I'm doing here...you'll always find that someone...it doesn't make it ethical, safe, correct or right! If you truely have the best interest of you baby at heart, you'll have her spayed now and not wait for the crap shoot. IF you don't, then you need to find another group to support what your doing here.....now go do the right thing!