Editing Dog (section)

==Reproduction==
The onset of sexual maturity in the female dog is marked by the first [[heat]], which occurs at the age of 7 to 11 months. Males develop their sexual competence at about the same age. Smaller dogs generally become sexually mature earlier than large breed dogs.

Dogs are subject to a pronounced half-yearly heat period. With an average heat interval of 5 to 7 months, they are among the seasonally monoestrous animals.

The sexual cycle is divided into 4 phases. With the onset of pre- oestrus , the vulva swells, and bloody to flesh-colored secretion emerges, which makes the bitch attractive for males. A deck readiness is not yet given. The duration of the pre-heat is - individually different - 4 to 21 days. It is followed by oestrus , which is characterized by the bitch's readiness to [[mate]] and fertility. The vaginal discharge becomes lighter and the bitch "presents" to the males. The heat phase is 2 to 12 days. Together with the heat, it is called heat. This is followed by the metestrusin the course of which regression and regeneration processes take place in the uterus over a period of 9-12 weeks. In the fourth phase ( anestrus ) there is no sign of sexual activity. This section lasts 2 to 6 months.

When the dog [[mates]], there is a remarkable behavior of "hanging". Upon penetration of the bitch, there is a strong swelling of the so-called [[knot]] of the dog, which is located at the lower end of the penis shaft. This has the effect that the penis is "wedged" and the two animals cannot separate from each other. As a result, the male animal descends from its partner and usually turns 180 °, so that both animals remain connected to each other with their rear ends facing each other for a period of up to 30 minutes.

The average gestation period of the bitch is 63 to 65 days, the number of puppies varies between 3 and 9 animals.