what is the reproductive age range of a dog?

We generally recommend waiting until dogs are at least two years old for their first breeding, primarily because that gives us an opportunity to complete their reproductive testing, such as OFA hips and elbows, and some other tests we feel are crucial to run before dogs are bred. There are some people who will breed younger. We never want to breed on the first heat cycle, although sometimes dogs plan things a little differently than we do so we want to be aware of that. In general, we also try not to breed much over the age of eight and recognize that dogs older than six tend to have about a 33% decrease in their fertility. So the older female and older male dogs have a decline in fertility as they age. Once we get past eight, we don't recommend breeding most females. The males can be continued to be bred as long as they are still able to produce sperm, and that could be well into their teens.

Peak fertility in a dog is between two and five years old.