When is the perfect age to breed dogs? by Dr. Suranjan Sarkar www.quora.com/When-is-the-perfect-age-to-breed-dogs
The healthy male is able to breed at any age, they remain fertile nearly lifelong.
Female dogs, on the other hand, become fertile while they attain puberty.
In other words, it can be said female dogs become fertile when their estrous cycle begins. Normally it is 15 months for most dogs. This is true for German Shepherds, Pugs etc. Labradors attain puberty at an earlier age, around 9 months.
Nowadays, dogs are attaining puberty earlier than 15 months owing to oestrogenic commercial food, some are successfully giving birth too but there are risks. Therefore, in my opinion, the perfect age to breed a dog is somewhere between 15 months to 7 years of age. seven years is the age of becoming old.
There is no general rule. As in the case of rottweiler females, they continue to grow till 24 months of age. Hence their perfect age to breed should be after 24 months.
The same is true for Siberian husky.
According to the American Kennel Club, responsible breeders do not breed their dog in their first heat. This is because they do not want to impose the stress of pregnancy that young.