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.
Domestic dogs tend to mature much earlier (6 to 8 months of age) and have significantly fewer hormonal changes, but the challenging behavior still exists, although it is typically less intense in most breeds compared to wolves. Hybrids can exhibit any combination of wolf or dog maturation rates and behavioral changes.