When to put a good dog up for breeding?

all the advice you've been given is good and valuable, but if I could be the devils advocate here for a minute, a dog proves its breed worthiness over several seasons over catching hogs, and the longer that dogs successful career, the higher the likelihood that its pups will continue its tradition of excellence. If you begin to routinely breed dogs that don't live passed 2 - 2 1/2 years old, you compound your issue of having dogs who lack the durability to live to maturity. If the dog in question is the end of a line, or even just the sole survivor of an irreplaceable litter then that could be a different story, but if its just an impressive young specimen, why not give it three years or so to fully mature and earn its right.

maybe this is not a problem you face, I am just throwing out my belief for public consideration