Hi,
Although they reach sexual maturity at 6-8 months of age it is best to wait until they are at least one year of age. Young males sometimes have trouble mating and the sperm being of low quality.
Also dog registrations such as the AKC will not register a dog that was breed before 7 months of age.
Walter
Breeder
Breeder and pet health consultant. Have spent a number of years with dog rescue, training and health