1 Records created or received by an individual, family or organisation (such as a government, cultural association, company or university) during its existence and selected to be kept permanently because they are considered to be of continuing value to society. 2  Unique and irreplaceable.
In domestic dogs, sexual maturity (puberty) occurs between the ages of 6 to 12 months for both males and females, although this can be delayed until up to two years of age for some large breeds. Pregnancy is possible as soon as the first estrus cycle, but breeding is not recommended prior to the second cycle.
If you are interested in breeding your dog, here are some suggested methods that breeders use. 1  Breed every 48 hours from first acceptance until she refuses to âstandâ. 2  Breed two or three times with a gap of 48 hours between breedings.  Breed on specific days, eg. Days 11 (from first sign of heat) and 13 or 12 and 14.