Dog reproduction

The onset of puberty in the female dog is characterized by the first heat, which occurs between the ages 7 to 14 months. Males attain their reproductive capacity around the same age. Smaller dogs are usually sexually mature earlier than large breed dogs.  Dogs are subject to a pronounced, approximately six-month breeding period.

With an average 5 to 7 months, they are among the seasonal animals.  The sexual cycle is divided into 4 phases. With the start of her season there is swelling of the vulva and the withdrawal of bloody secretion which makes the female attractive to males. The duration of Vorbrunst is usually 4 to 21 days.  This is followed by heat which is characterized by the bitch and fertility. The vaginal discharge is lighter and the female is “presented” to the dogs.

The stage of estrus is 2 to 12 days. Together with being in heat. This is followed by the metestrus, made in the course over a period of 9-12 weeks of involution and regeneration processes of the uterus.

In the fourth phase (anestrus) there lacks any sign of sexual activity. This section lasts for 2 to 6 months.   When it comes to the mating of a dog their behavior of the “hanging” is remarkable.   On penetration of the bitch there is a strong swelling of the so-called “node” (anatomic eyeball glans) of the males, which represents the thickened base of the penis with erectile tissue.

This has the effect that the penis is “keyed” and the two animals can not separate. Consequently, the male descends after ejaculation off his partner and turns normally around 180° so that both animals remain for a period of up to 30 minutes with the backsides facing each other connected. The slope gives the sperm a head start over those of subsequent males.  The average gestation period of the bitch amounts to 63 to 65 days, the number of pups per litter varies from approximately 3 to 12 animals.