A female dog reaches sexual maturity any time between 6 and 18 months. A Yorkie would mature faster than a Great Dane. The smaller the dog, the faster it matures. A bitch goes into heat every 6 months, except for the Basenji which only goes into heat once a year....same as a wolf.
A male dog reaches sexual maturity between the ages of 4 to 6 months.
The of four stages of Estrus (or "heat") are as follows:
PROESTRUS: "coming into heat stage"; females attract males but are not receptive to them; vulva is
swollen; estrogen levels increase; lasts 6-9 days
ESTRUS: "standing heat"; will stand for male and be receptive; estrogen levels drop; progesterone
levels increase; lasts about 6 days
METESTRUS: "going out of heat"; only happens if not pregnant; progesterone level returns to normal;
lasts about 60 days
ANESTRUS: "silent period"; normal state; lasts about 4 months |