Gestation (Pregnancy) Period in Dogs

Pregnancy in the dog (all breeds) lasts about 2 months: 60-64 days.
The canine reproductive life varies greatly from breed to breed with regard to onset of puberty, however. Small breed dogs typically start having estrus (heat) cycles earlier, at 4-6 months of age, and large breeds typically start later, at 12 to 24 months of age. The estrus cycles vary between each individual dog, average of 6 to 12 days. Some dogs as few as 2 days, some dogs cycle as long as 21 days.1
Female dogs cycle throughout their life, they do not experience menopause (reproductive cycles ceasing with age) as human females do.